Volunteer armies were raised for the Florida Seminole Wars, Black Hawk War, Creek Wars and other conflicts
Ancestry has a database for Compiled Military Service Records for American Volunteer Soldiers, Mexican War, 1845-1848.
Fold3 contains the index for CMSR’s (Compiled Military Service Records) and the Indian Wars Service Record Index.
- Fold3 has digitized the Mexican War Service Record Index and has the full CMSR for Arkansas, Mississippi, Pennsylvania, Tennessee, Texas, and the Mormon Battalion
NARA (National Archives and Records Administration)
- Military service records of soldiers who fought in volunteer organizations during the Mexican War are available here
- Muster Rolls of Volunteer Organizations During the Civil War, Mexican War, Creek War, Cherokee Removal, and other Wars, 1836-1866, are available here
The National Park Service’s Palo Alto Battlefield National Historical Park has information on more than 85,000 US and Mexican troops who served in the War.