Q: I’m trying to find out info about a Seneca Indian in Civil War service. Where do you recommend I look?
A: We seldom hear about American Indian participation in the Civil War, but up to 29,000 Native Americans served on either side. A Seneca lawyer and Union general, Ely S. Parker, was the military secretary for Ulysses S. Grant and actually drew up the articles of surrender signed by Robert E. Lee at Appomattox Courthouse. (The City of Alexandria, Va. website has more information on Parker.)
Geography matters
After the American Revolution and several treaties, most Senecas settled in what are now two tribes in western New York. The state archives has an index of Civil War soldiers from New York; you will also find useful information at the New York State Military Museum.
A third group of Senecas migrated to Ohio and were removed to the Indian Territory of present-day Oklahoma. Some of these tribe members served in the Union’s 2nd Oklahoma Regiment, Indian Home Guard. You can read about the Indian Home Guard and about Oklahoma’s role in the war at Family Search.
To learn more about Indians in the war, see the American Indians in the Civil War wiki page at Family Search. To see which regiment your ancestor served with, look him up at the Civil War Soldiers & Sailors System.