District of Columbia History
The following important events in the history of the District of Columbia affected political boundaries, record keeping, and family movements.
- 1788-1791: Maryland ceded parts of Montgomery (including Georgetown) and Prince George counties to the United States, and Virginia ceded part of Fairfax county (including the town of Alexandria). Those counties continued to govern the area until about 1801, but Virginia kept permanent custody of the records for Alexandria.
- 1800: Congress, the President, and a staff of about 140 people moved from Philadelphia to Washington.
- 1801: Two counties were established in the District: Washington County, east of the Potomac, and Alexandria County, on the west side of the river. The City of Washington was incorporated in 1802. Georgetown wills and deeds continued to be registered in Montgomery County, Maryland, until the late nineteenth century.
- 1814: During the War of 1812, the British captured Washington and burned most of the public buildings and records.
- 1846: The portion originally given by Virginia was returned to that state.
- 1861-1865: Although defended by federal troops during the Civil War, Washington was several times threatened by Confederates. The civilian population of Washington more than doubled during the 1860s.
- 1871: Congress changed the city's status to that of a federal territory.
- 1895: Georgetown was merged into the city of Washington. The boundaries of Washington became coextensive with those of the District of Columbia.
- 1898: Over 300,000 men were involved in the Spanish-American War which was fought mainly in Cuba and the Philippines.
- 1917–1918: More than 26 million men from the United States ages 18 through 45 registered with the Selective Service. World War I over 4.7 million American men and women served during the war.
- 1930's: The Great Depression closed many factories and mills. Many small farms were abandoned, and many families moved to cities.
- 1940–1945: Over 50.6 million men ages 18 to 65 registered with the Selective Service. Over 16.3 million American men and women served in the armed forces during World War II.
- 1950–1953: Over 5.7 million American men and women served in the Korean War.
- 1950's–1960's The building of interstate highways made it easier for people to move long distances.
- 1964–1972: Over 8.7 million American men and women served in the Vietnam War.
Histories are great sources of genealogical information. Many contain biographical information about individuals who lived in the area, including:
Some of the most valuable sources for family history research are local histories. Published histories of towns, counties, and states usually contain accounts of families. They describe the settlement of the area and the founding of churches, schools, and businesses. You can also find lists of pioneers, soldiers, and civil officials. Even if your ancestor is not listed, information on other relatives may be included that will provide important clues for locating your ancestor. A local history may also suggest other records to search. Local histories are extensively collected by the Family History Library, public and university libraries, and state and local historical societies.
State Histories Useful to Genealogists
Good genealogists strive to understand the life and times of their ancestors. In this sense, any history is useful. But certain kinds of state, county, and local histories, especially older histories published between 1845 and 1945, often include biographical sketches of prominent individuals. The sketches usually tend toward the lauditory, but may include some genealogical details. If these histories are indexed or alphabetical, check for an ancestor's name. An examples for the District of Columbia is:
- Washington, Past and Present is a good history of the District of Columbia. 
United States History
The following are only a few of the many sources that are available:
- The Almanac of American History,   This provides brief historical essays and chronological descriptions of thousands of key events in United States history.
- Dictionary of American History, Revised ed   This includes historical sketches on various topics in U.S. history, such as wars, people, laws, and organizations. A snippet view is available at Google books.
- Webster's Guide to American History: A Chronological, Geographical, and Biographical Survey and Compendium    This includes a history, some maps, tables, and other historical information.
To find more books and articles about District of Columbia 's history use the Internet Google search for phases like "District of Columbia history." Family History Library Catalog Surname Search lists many more histories under topics like:
- DISTRICT OF COLUMBIA- HISTORY
- DISTRICT OF COLUMBIA, BIBLIOGRAPHY
- District of Columbia - Wikipedia
- History of District of Columbia
- Register of History Places in the District of Columbia
- Filby, P. William. A Bibliography of American County Histories. Baltimore: Genealogical Publishing, 1985. (FHL book 973 H23bi)
- Kaminkow, Marion J. United States Local Histories in the Library of Congress. 5 vols. Baltimore: Magna Charta Book, 1975-76. (FHL book 973 A3ka.)
- John Clagett Proctor, Washington, Past and Present, Four Volumes. (New York, NY: Lewis Historical Publishing Company, 1930; FHL book 975.3/W1 H2p).
- Schlesinger, Jr., Arthur M. The Almanac of American History. Greenwich, Conn.: Bison Books, 1983. (FHL book 973 H2alm)
- Dictionary of American History, Revised ed., 8 vols. New York: Charles Scribner's Sons, 1976. (FHL book 973 H2ad.)
- Webster's Guide to American History: A Chronological, Geographical, and Biographical Survey and Compendium. Springfield, Mass.: G&C Merriam, 1971. (FHL book 973 H2v)
- Limited view at Google Books
- Writings on American History By American Historical Association, Library of Congress, United States National Historical Publications Commission, Published by KTO Press, 1921 FHL book 973 H23w