On April 12, 1861, Confederate troops fired on Union-held Fort Sumter near Charleston, S.C., and changed the course of history. This month marks the 150th anniversary of that event, the beginning of the American Civil War (1861-1865).

There were approximately 6.3 million men who fought in the Army or Navy for the Union or Confederacy during the Civil War. These soldiers and sailors were generally men born between 1821 and 1843(ages 18 to 40), although men older and younger also served.

Military service records and pension file records are the two basic records available when searching for an ancestor who served in the military during the Civil War. Starting with the Civil War, these records include personal information and more details than records from previous wars about places and dates of a soldier`s service.

Compiled military service records for Union and Confederate soldiers from the Civil War (1861-1865) are housed at the National Archives in Washington, D.C. The compiled records usually consist of muster roll cards. These cards will include rank, age, place of residence, occupation, muster in date, pay and muster out date. Copies of Union and Confederate records can be obtained from by using NAFT Form 86 or ordered online at archives.gov.

Confederate records have been microfilmed and also are available through the Family History Library. In addition to the federal records, most states kept military service records, and those should be ordered from the appropriate state agency.

Pension records generally contain much more genealogical information than military records. To qualify for a pension, a veteran had to submit personal information about himself, his wife and family. The files contain different documents depending on the situation and when the application was made. The veteran, his widow, minor children or parent might have applied for the pension. Right after the war, only those who had serious injuries or widows were granted a pension. Laws were relaxed as the years went by, and eventually almost all living Civil War veterans qualified for a pension. Union pension files are housed at NARA in Washington, D.C. Copies can be ordered using NATF Form 85 or ordered online at archives.gov. Confederate pensions were not granted by the federal government, but were granted by individual states. Contact the appropriate state archive for information.

Ancestry.com and Footnote.com both have indexes to some of these records. Check their Web sites for details about specific databases.

Additional sources for Civil War research are:

Many regimental histories were written in the years immediately following the war. These histories contain firsthand accounts and are invaluable, even if your ancestor is not mentioned by name. The Library of Congress has a list of these histories at loc.gov/rr/main/uscivilwar.

A useful resource is “The War of the Rebellion: A Compilation of the Official Records of the Union and Confederate Armies,” which was first published in 1880 by the U.S. government. It contains battle reports, maps and correspondence from the war. The 1900 edition is available for free download from the Google ebookstore.

Records of veterans` groups, such as the Grand Army of the Republic and United Confederate Veterans Association, are helpful. These records are generally found in the state where the veteran lived, rather than the state where he served.

The Library of Virginia has an index to the Confederate Veteran Magazine 1893-1932(lva.virginia.gov/public/guides/opac/aboutvetmagazine.htm). The magazine contains activities of Confederate veteran organizations, veteran personal histories and battle accounts.

There are a lot of Web sites that contain Civil War information or links to Civil War sites. Here are a few of my favorites:

National Park Service “The American Civil War” (nps.gov/civilwar/civilwar.htm) — offers historical information, special events, exhibits, multimedia experiences and education opportunities about the Civil War. It also hosts the Soldiers and Sailors System, which is a searchable index for both Union and Confederate soldiers and sailors (itd.nps.gov/cwss/).

“Civil War 150th Anniversary” sponsored by the Civil War Trust (civilwar.org/150th-anniversary) — is full of maps, photos, Civil War book resources, and even has “battle apps” for the iPhone.

“The American Civil War Homepage” (http://sunsite.utk.edu/civil-war/warweb.html) — is a collection of links that identify electronic files about the Civil War.

No matter which side of the conflict your ancestor served, there are many resources to help with your research.

Upcoming events

Broomfield Genealogy Society — 7 to 9 p.m. April 21 at Mamie Doud Eisenhower Public Library, 3 Community Park Road. Jim Walsh will present “Life & Labor of the Leadville Irish.” Visitors welcome.

Julie Miller is a certified genealogist. She is a genealogy researcher, lecturer, and writer. If you have a genealogy question, send it tojulie@jpmresearch.com.