The following important events in the history of Missouri affected political boundaries, record keeping, and family movements.
- 1735: French lead miners established the first permanent white settlement at Sainte Genevieve.
- 1763: France ceded the Missouri area to Spain. French fur traders founded St. Louis in 1764.
- 1800: Spain returned the region to France.
- 1803: France sold Missouri to the United States as part of the Louisiana Purchase. Missouri was part of the Louisiana Territory after 1805.
- 1812: (June 4,) Congress created the Missouri Territory. Many families left after earthquakes and other disasters.
- 1821: (August 10,) Missouri became a state.
- 1837: The Osage Indians ceded land
- 1837: The Platte Purchase added six northwestern counties to the state.
- Oregon Trail and Santa Fe Trail start at Independence, Missouri
- 23 April 1860 - 24 October 1861: Pony Express
- 1861-1865: During the Civil War most of the citizens supported the Union, although several counties seceded. Troops from Missouri served in both the Confederate and the Union forces.
- 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. The United States Research "History" page cites nationwide bibliographies of local histories which include histories of Missouri.
- For a list of published county histories, see A Bibliography of Missouri County Histories and Atlases 
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 laudatory, but may include some genealogical details. If these histories are indexed or alphabetical, check for an ancestor's name. Some examples for the State of Missouri:
- Major research centers have histories of the state and its counties. An especially helpful source for studying the history of Missouri before statehood is A History of Missouri from the Earliest Explorations and Settlements until the Admission of the State into the Union 
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.
- The Pony Express
Pony Express riders carried the U.S. Mail on horseback. There were approximately 80 of them. There were support personnel as well that numbered over 400. The Pony Express Route Covered Parts of: California, Colorado, Kansas, Missouri, Nebraska, Utah and Wyoming.
Pony Express Riders Biographies:
By Name Include Some Photos
- 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 Missouri 's history use the Internet Google search for phases like "Missouri history." Family History Library Catalog Surname Search lists many more histories under topics like:
- MISSOURI - HISTORY
- MISSOURI, [COUNTY] - HISTORY
- MISSOURI, [COUNTY], [TOWN] - HISTORY
- MISSOURI, BIBLIOGRAPHY
- Paul O. Selby,A Bibliography of Missouri County Histories and Atlases, 2d ed. (Kirksville, Missouri: Northeast Missouri State Teachers College, 1966; Family History Library book 977.8 A1 No. 145).
- 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.)
- Louis Houck, A History of Missouri from the Earliest Explorations and Settlements until the Admission of the State into the Union, Three Volumes. (Chicago, Illinois: R. R. Donnelley, 1908; Family History Library book 977.8 H2h; vols. 1-2 on film 1697679 items 2-3; vol. 3 on film 1320710).
- 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