The following important events in the history of Arizona affected political boundaries, record keeping, and family movements.
- 1539: Marcos de Niza a Spanish Franciscan Friar was first to explore Arizona.
- 1776: :The Spanish established a garrison at Tucson. The Spanish established a garrison at Tucson.
- 1821: Arizona became a part of Mexico. Apache troubles eliminated white settlements except in Tucson.
- 1846: The Mormon Battalion built Cooke's Wagon Road, south of the Gila River. The road became a favorite route into Arizona and California for early prospectors and pioneers.
- 1846: U.S. Military under command of Col. Alexander W. Doniphan engaged the Navajo at Bear Springs.
- 1848-1853: Mexico ceded the portion of Arizona north of the Gila River to the United States. This became part of New Mexico Territory in 1850. In 1853, the Gadsden Purchase added the area south of the Gila.
- 1862: Indian battle of Apache Pass
- 1864: Kit Carson, led a U.S. army against the Navajo Indians. The army killed the sheep and burned their crops forcing the tribe to surrender or face starvation. The Navajo were marched to Fort Sumner at Bosque Redondo, New Mexico. The march became known as "The Long Walk". Eight thousand survived the march but many others died.
- 1863-1866: Arizona was organized as a separate territory. The first four counties were organized in 1864. In 1866, the northwestern part of Arizona Territory was transferred to the new state of Nevada.
- 1886: (September 4) Apache Indian Chief, Geronimo, captured by Federal Troops under General Miles in Arizona, ending the last major Indian War. Geronimo had led his band on a six month escape from San Carlos reservation in Arizona.
- Battle of Bull Run (Indian & federal troops)
- Battle of Picacho Pass (Indian & federal troops)
- Battle of Skull Cave (Indian & federal troops)
- 1871: Camp Grant Massacre
- 1873: Apache removal by U.S. Army under direction of Kit Carson.
- 1882: Battle of Big Dry Wash
- 1870-1910: The non-Indian population of Arizona increased from fewer than 10,000 to over 200,000 as settlers moved in from many states and countries.
- 1898: Over 300,000 men were involved in the Spanish-American War which was fought mainly in Cuba and the Philippines.
- 1912: (February 14,) Arizona became a state
- 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 Arizona.
A bibliography that includes some local histories is Arizona Gathering II, 1950-1969: An Annotated Bibliography. 
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 Arizona are:
- History of Arizona. 
- Arizona: The History of a Frontier State 
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 Arizona 's history use the Internet Google search for phases like "Arizona history." Family History Library Catalog Surname Search lists many more histories under topics like:
- ARIZONA - HISTORY
- ARIZONA, [COUNTY] - HISTORY
- ARIZONA, [COUNTY], [TOWN] - HISTORY
- ARIZONA, BIBLIOGRAPHY
- Donald M. Powell, Arizona Gathering II, 1950-1969: An Annotated Bibliography. Tucson, Arizona: University of Arizona Press, 1973. (Family History Library book 979.1 A3pa).
- 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.)
- Farish, Thomas Edwin. History of Arizona. Eight Volumes, San Francisco, California: Filmer Brothers Electrotype Company, 19--? Reprint of Phoenix, Arizona: N.p., 1915-18. ( Family History Library book 979.1 H2f; v. 1-4; on film 934825 items 1-4.)
- Wyllys, Rufus Kay. Arizona: The History of a Frontier State. Phoenix, Arizona: Hobson and Herr, 1950. ( Family History Library book 979.1 H2w.)
- 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