How to use this page: Epidemic history is context, not proof of an individual’s cause of death. Early disease names were often imprecise, and modern diagnoses cannot always be assigned confidently to historical descriptions. Death totals are approximate unless otherwise noted. A blank death field means that no reliable figure was included in the working chronology or selected sources.
Why genealogists should care
When an epidemic may be hiding in the family record
An epidemic can explain patterns that otherwise look mysterious. When several relatives vanish from records within a short span, children suddenly appear in another household, guardians are appointed, a widowed spouse remarries unusually quickly, or a family leaves an affected town, the disease history of that place and year is worth checking.
- Compare death, burial, probate, guardianship, church, and newspaper records for the same weeks or months.
- Look beyond the exact modern disease name. Historical records may use terms such as ague, grippe, bilious fever, throat distemper, or enteric fever.
- Pay attention to nearby households. Epidemics often become visible in clusters of neighbors, schoolchildren, military units, or church burial registers.
- Remember that people sometimes fled affected communities, so an epidemic may explain a temporary disappearance rather than a death.
1655 to the present
Searchable Epidemic Timeline
The chronology began with my older Mid-Atlantic epidemic spreadsheet and has been cleaned, reorganized, and selectively cross-checked against historical and public-health sources. Rows shaded pale gold have a Delaware, Maryland, Virginia, Pennsylvania, Washington, D.C., or broader Mid-Atlantic connection.
| Date | Event | Pathogen / Cause | Area Affected | Deaths | Notes |
|---|---|---|---|---|---|
| 1655-1658 | Malarial fevers | Plasmodium parasites | Delaware (especially New Amstel / present-day New Castle area) | — | Malarial fevers were common during the Dutch period; Delaware historical sources describe heavy illness in 1657–1658 after extraordinary rainfall. [source] |
| 1679-1680 | Smallpox Epidemic | Variola virus | Virginia | — | — |
| 1713-1715 | North American measles epidemic | Measles virus | British colonies and New France | Unknown | A serious measles epidemic began in Boston in 1713 and spread through other colonies and New France in 1714–1715. [source] |
| 1715-1725 | Smallpox Epidemic | Variola virus | Most of the colonies | — | — |
| 1723-1730 | Smallpox Epidemic | Variola virus | Boston, New York, Philadelphia | — | — |
| 1732-1733 | Influenza epidemic | Influenza virus | Thirteen Colonies / North America | Unknown | The working spreadsheet carried modern city labels in this row; the broader historical event is better described as an epidemic across colonial North America. |
| 1734 | Yellow Fever | Yellow fever virus (Flavivirus) | Virginia | — | Mosquito-borne. |
| 1741 | Yellow Fever | Yellow fever virus (Flavivirus) | Virginia | — | — |
| 1747 | Measles | Measles virus | CT, NY, PA, SC | — | — |
| 1759 | North American measles outbreak | Measles virus | North America | Unknown | — |
| 1761 | Influenza epidemic | Influenza virus | North America | — | — |
| 1762 | Yellow Fever | Yellow fever virus (Flavivirus) | Philadelphia | — | — |
| 1763 | “Throat distemper” (diphtheria) | Corynebacterium diphtheriae | Philadelphia | — | “Throat distemper” was a historical term used for severe throat disease, often identified as diphtheria. |
| 1772 | North American measles epidemic | Measles virus | North America | 1,080 | — |
| 1783 | “Bilious disorder” / pestilential fever | Unknown (historical diagnosis) | Dover, Delaware; Fell’s Point, Baltimore | — | Contemporary and later accounts describe severe “bilious” or pestilential fever. The precise modern diagnosis is uncertain. [source] |
| 1788 | Measles | Measles virus | Philadelphia and New York | — | — |
| 1789 | Influenza epidemic | Influenza virus | Philadelphia and Atlantic America | — | Benjamin Rush described the rapid spread of influenza in Philadelphia in autumn 1789. [source] |
| 1789 | Scarlatina / scarlet fever | Streptococcus pyogenes | Philadelphia | — | — |
| 1793 | Influenza epidemic | Influenza virus | Virginia | ≈500 | Older epidemic chronologies report about 500 deaths in five Virginia counties within four weeks. |
| 1793 | Philadelphia yellow fever epidemic | Yellow fever virus (Flavivirus) | Philadelphia | 5,000+ | One of the best-documented yellow fever disasters in U.S. history; more than 5,000 Philadelphians died. [source] |
| 1794 | Yellow Fever | Yellow fever virus (Flavivirus) | Philadelphia, Baltimore | — | — |
| 1796-1797 | Yellow Fever | Yellow fever virus (Flavivirus) | Philadelphia | — | — |
| 1798 | Yellow Fever | Yellow fever virus (Flavivirus) | Philadelphia | — | — |
| 1820-1823 | “Fever” epidemic (historical label) | Unknown | United States; reported from the Schuylkill River region outward | — | The original spreadsheet labeled this yellow fever. Older genealogy timelines list the event more cautiously as “fever,” so the specific diagnosis is left open here. [source] |
| 1826-1837 | Second cholera pandemic | Vibrio cholerae | Asia, Europe, and North America | 100,000+ | Often called “Asiatic cholera” in nineteenth-century records; spread chiefly through contaminated food and water. |
| 1837 | Typhus outbreak | Rickettsia prowazekii | Philadelphia | — | Epidemic typhus is louse-borne. |
| 1841 | Yellow Fever | Yellow fever virus (Flavivirus) | United States (esp severe in the south) | — | — |
| 1846-1860 | Third cholera pandemic | Vibrio cholerae | Worldwide | 1,000,000+ | — |
| 1847-1848 | Influenza epidemic | Influenza virus | Worldwide | Unknown | — |
| 1850 | Yellow Fever | Yellow fever virus (Flavivirus) | United States | — | — |
| 1850-1851 | Influenza epidemic | Influenza virus | United States | — | — |
| 1852 | Yellow Fever | Yellow fever virus (Flavivirus) | United States | — | New Orleans was especially hard-hit. |
| 1855 | Yellow Fever | Yellow fever virus (Flavivirus) | United States | — | — |
| 1857-1859 | Influenza epidemic | Influenza virus | Europe, North America, South America | Unknown | — |
| 1860-1861 | Smallpox epidemic | Variola virus | Pennsylvania | — | — |
| 1861-1865 | Civil War typhoid fever epidemic | Salmonella enterica serovar Typhi | United States, especially military camps | ≈29,000 Union troops | Typhoid spread readily through fecally contaminated food and water in crowded camps. Historical Army totals vary with diagnostic classification. [source] |
| 1865-1873 | Recurring cholera epidemics | Vibrio cholerae | Baltimore, Memphis, Washington, D.C., and other U.S. cities | — | Part of the fourth cholera pandemic era. |
| 1865-1873 | Recurring smallpox epidemics | Variola virus | Philadelphia, New York, Boston, New Orleans, and other U.S. cities | — | — |
| 1881 | Lower Delaware smallpox outbreak | Variola virus | Sussex County, Delaware, near the Maryland line | — | Newspapers reported about twenty cases around Selbyville and continuing spread in Baltimore Hundred; quarantine fears disrupted travel and commerce. [source] |
| 1889-1892 | “Russian flu” pandemic | Usually attributed to influenza; HCoV-OC43 hypothesis disputed | Worldwide | ≈1,000,000 | Contemporaries called it influenza. A later coronavirus hypothesis has been proposed, but recent molecular reassessment has challenged that identification. [source] |
| 1901 | Lower Delaware / Delmarva smallpox outbreak | Variola virus | Lower Delaware, with concern along the Maryland–Delaware line | — | Sussex County communities imposed quarantines; contemporary reports mention Seaford and a smallpox scare in Delmar. [source] |
| 1916 | U.S. polio epidemic | Poliovirus | United States | 7,130 | The United States recorded 27,363 paralytic cases and 7,130 deaths in 1916. [source] |
| 1916-1926 | Encephalitis lethargica epidemic | Unknown | Worldwide | Uncertain | Also called “sleeping” or “sleepy sickness” (not African trypanosomiasis). Estimates of cases range widely; the cause remains unknown. [source] |
| 1918-1919 | 1918 influenza pandemic | Influenza A(H1N1) virus | Worldwide | 50,000,000+ | Often called the “Spanish flu.” CDC estimates at least 50 million deaths worldwide and about 675,000 in the United States. [source] |
| 1948-1952 | Major U.S. polio epidemic years | Poliovirus | United States | ≈9,000 (1948–1952) | The 1952 peak alone brought roughly 58,000 cases and about 3,000 deaths. [source] |
| 1957-1958 | Asian flu pandemic | Influenza A(H2N2) virus | Worldwide | ≈1,100,000 | CDC estimates about 1.1 million deaths worldwide and 116,000 in the United States. [source] |
| 1968-1970 | Hong Kong flu pandemic | Influenza A(H3N2) virus | Worldwide | ≈1,000,000 | CDC estimates about 1 million deaths worldwide and about 100,000 in the United States. [source] |
| 1972-1973 | “London flu” epidemic | Influenza A(H3N2), A/England/42/72 variant | United States and other countries | ≈6,000–23,000 U.S. | A major epidemic caused by an H3N2 drift variant; it was not a new pandemic virus. Library of Congress historical material cites roughly 6,000–23,000 U.S. flu/pneumonia deaths. [source] |
| 1981-present | HIV/AIDS pandemic | Human immunodeficiency virus (HIV) | Worldwide | ≈44,000,000+ | Ongoing. UNAIDS estimates more than 44 million AIDS-related deaths since the start of the epidemic (through 2025). [source] |
| 2002-2003 | SARS outbreak | SARS coronavirus (SARS-CoV) | 29 countries | 774 | WHO/CDC recorded about 8,096–8,098 probable cases and 774 deaths; the global outbreak was contained in July 2003. [source] |
| 2009 | 2009 H1N1 influenza pandemic | Influenza A(H1N1)pdm09 virus | Worldwide | 151,700–575,400 | CDC-led estimates place worldwide deaths during the first year in this range. [source] |
| 2012-present | Middle East respiratory syndrome (MERS) | MERS coronavirus (MERS-CoV) | Worldwide; most cases linked to the Arabian Peninsula | ≈36% of reported cases | Ongoing but uncommon. WHO reports more than 2,600 laboratory-confirmed cases since 2012; about 36% of reported cases have died. [source] |
| 2019-present | COVID-19 pandemic | SARS-CoV-2 | Worldwide | 7,000,000+ reported | WHO ended the COVID-19 public-health emergency in May 2023, not the disease itself. Nearly 7 million deaths had been officially reported by late 2023; WHO estimated the true toll was several times higher. [source] |
Reading old records
Disease Guide for Genealogists
The original spreadsheet included a beginning disease-reference sheet. This expanded version adds common symptoms, transmission, and the kinds of historical terms or record patterns a genealogist may encounter.
Yellow fever
Cause: Yellow fever virus
Typical symptoms: Fever, chills, severe headache, back and body aches; severe cases can cause jaundice, bleeding, shock, and organ failure.
How it spreads: Bites of infected mosquitoes.
Genealogy note: Look for terms such as yellow fever, yellow jack, or epidemic fever in port communities. Seasonal outbreaks could empty neighborhoods and prompt flight or quarantine.
Influenza
Cause: Influenza viruses
Typical symptoms: Sudden fever or chills, cough, sore throat, aches, headache, and fatigue; pneumonia may follow.
How it spreads: Primarily respiratory droplets and aerosols; close contact facilitates spread.
Genealogy note: Historical records may use influenza, grippe, or epidemic catarrh. Several household deaths over a short period may reflect influenza or secondary pneumonia.
Cholera
Cause: Vibrio cholerae
Typical symptoms: Profuse watery diarrhea, vomiting, cramps, and rapid dehydration.
How it spreads: Food or water contaminated with the bacterium.
Genealogy note: Nineteenth-century records may say Asiatic cholera. Be cautious with cholera morbus, which was also used for severe non-cholera gastrointestinal illness.
Smallpox
Cause: Variola virus
Typical symptoms: High fever and body aches followed by a characteristic rash that progressed to pustules and scabs.
How it spreads: Mainly prolonged face-to-face respiratory contact; contaminated bedding, clothing, or scabs could also spread infection.
Genealogy note: Quarantine, pest houses, vaccination campaigns, and sudden clusters of deaths can be important clues. Smallpox was eradicated globally in the twentieth century.
Encephalitis lethargica
Cause: Unknown
Typical symptoms: High fever, headache, double vision, profound lethargy, abnormal movements, weakness, and sometimes behavioral or psychiatric changes.
How it spreads: Unknown.
Genealogy note: Often called sleeping sickness or sleepy sickness; do not confuse it with African trypanosomiasis. Some survivors later developed post-encephalitic parkinsonism.
Typhus
Cause: Rickettsia prowazekii (epidemic typhus)
Typical symptoms: Abrupt fever, severe headache, body aches, rash, and sometimes confusion.
How it spreads: Epidemic typhus is spread by infected body lice.
Genealogy note: Especially associated historically with war, crowding, displacement, prisons, and poor access to bathing or clean clothing.
Measles
Cause: Measles virus
Typical symptoms: High fever, cough, runny nose, red eyes, and a spreading rash.
How it spreads: Airborne and respiratory spread; extraordinarily contagious.
Genealogy note: Before vaccination, childhood epidemics were common. Parish and family records may show several children sick or dying within the same household or neighborhood.
Typhoid fever
Cause: Salmonella Typhi
Typical symptoms: Prolonged high fever, weakness, stomach pain, headache, constipation or diarrhea, and sometimes a rose-colored rash.
How it spreads: Food or water contaminated by feces from an infected person or carrier.
Genealogy note: Historical records may say enteric fever. During the Civil War, diagnostic labels such as typho-malarial fever can complicate interpretation.
Malaria
Cause: Plasmodium parasites
Typical symptoms: Recurring fever and chills, sweating, headache, weakness, and sometimes severe anemia or neurologic illness.
How it spreads: Bites of infected Anopheles mosquitoes.
Genealogy note: Older records may use ague, intermittent fever, marsh fever, or swamp fever. Tidal and marshy environments made malaria historically relevant to Delmarva.
Diphtheria
Cause: Corynebacterium diphtheriae
Typical symptoms: Sore throat, fever, swollen neck, and a thick membrane in the throat; severe disease can damage the heart and nerves.
How it spreads: Respiratory droplets and close contact.
Genealogy note: Older sources may call severe outbreaks throat distemper. Childhood mortality could be high before vaccination and antitoxin.
Scarlet fever
Cause: Streptococcus pyogenes
Typical symptoms: Fever, sore throat, sandpaper-like rash, and a bright red or 'strawberry' tongue.
How it spreads: Respiratory droplets and close contact with infected secretions.
Genealogy note: Common historical labels include scarlet fever, scarlatina, and sometimes scarletina. Family clusters are common in school-age children.
Polio
Cause: Poliovirus
Typical symptoms: Most infections are mild or silent; severe disease can cause meningitis, weakness, paralysis, and respiratory failure.
How it spreads: Person-to-person, especially fecal-oral spread.
Genealogy note: Look for references to infantile paralysis, quarantines, summer outbreaks, braces, iron lungs, and later post-polio disability.
A few historical terms worth recognizing
- Ague / intermittent fever
- Often used for malaria or malaria-like recurring fever and chills.
- Bilious fever / bilious disorder
- A broad historical diagnosis, not a single modern disease. It could be applied to several severe febrile illnesses.
- Grippe
- An older name for influenza.
- Throat distemper
- A historical term often associated with diphtheria, especially in childhood epidemics.
- Enteric fever
- Usually typhoid or paratyphoid fever.
- Typho-malarial fever
- A nineteenth-century diagnostic category used when typhoid and malaria were difficult to distinguish clinically.
- Cholera morbus
- Historically used for severe gastroenteritis and not necessarily true epidemic cholera caused by Vibrio cholerae.
- Infantile paralysis
- Poliomyelitis (polio).
- Sleeping / sleepy sickness
- May refer to encephalitis lethargica in early twentieth-century records; context matters because the same phrase can refer to African trypanosomiasis.
- Consumption
- Usually tuberculosis; included here because influenza and other epidemics could be especially dangerous to people already described as consumptive.
Sources and Research Notes
This page began with an older working spreadsheet titled Pandemics-MidAtlantic. I preserved its genealogy-first purpose while correcting spelling, standardizing disease names, clarifying several modern death estimates, and avoiding certainty where historical diagnoses remain unclear. The following sources were used for selected checks and the disease guide; they are not intended to imply that every early entry has been exhaustively documented here.
Historical chronology and Mid-Atlantic context
- Delaware Public Archives, Man and Nature in Delaware — historical discussion of malarial fevers during the Dutch period.
- Mazan, Gagnon, and Desjardins, “The Measles Epidemic of 1714–1715 in New France”, Canadian Studies in Population.
- The USGenWeb Project, Epidemics in U.S. History — a long-running genealogy-oriented chronology useful for identifying years and places that merit further research.
- Noah Webster, A Brief History of Epidemic and Pestilential Diseases (1800) — contemporary-era discussion of the 1783 pestilential fever.
- Benjamin Rush, “An Account of the Influenza”, describing Philadelphia in 1789–1791.
- National Park Service, A City Response to Yellow Fever, and CDC, History of Mosquitoborne Diseases in the United States.
- U.S. Army Medical Department, historical typhoid statistics, and the National Museum of Civil War Medicine, Typhoid Fever — One of the Civil War’s Deadliest Diseases.
- Contemporary newspaper reports summarized by Sussex County Delaware Genealogy and History document the 1881 lower-Delaware smallpox outbreak.
- Contemporary newspaper reports summarized by Delaware Genealogy and History: Epidemics and the Delmar Historical and Art Society document the 1901 lower-Delaware quarantine and Delmar smallpox scare.
Twentieth- and twenty-first-century epidemics
- PubMed-indexed scholarship: Coronavirus as the Possible Causative Agent of the 1889–1894 Pandemic and a later critical reassessment of the HCoV-OC43 hypothesis.
- National Park Service, Polio — 1916 U.S. case and death figures.
- NIH Genetic and Rare Diseases Information Center, Encephalitis lethargica.
- CDC, 1918 Pandemic (H1N1 virus).
- National Archives / DocsTeach, Distribution of Polio in the United States, 1952.
- CDC, 1957–1958 Pandemic (H2N2 virus).
- CDC, 1960–1999 Highlights in the History of Avian Influenza — 1968 H3N2 pandemic figures.
- Library of Congress, Herblock Looks at 1973, with historical context and mortality estimates for the “London flu” epidemic.
- CDC, Severe Acute Respiratory Syndrome (SARS).
- CDC, First Global Estimates of 2009 H1N1 Pandemic Mortality.
- World Health Organization, MERS-CoV Dashboard.
- World Health Organization, COVID-19 epidemiological update, 22 December 2023, and WHO remarks on the end of the global public-health emergency in May 2023.
- UNAIDS, Global HIV & AIDS statistics.
Disease descriptions and transmission
The disease guide uses current background information from the Centers for Disease Control and Prevention on yellow fever, influenza, cholera, smallpox, epidemic typhus, measles, and typhoid fever, together with NIH material on encephalitis lethargica.
Historical research resource only: This page is intended to help interpret historical records and is not medical advice or a guide to diagnosing illness in living people.