A.The National Park Service has given you a great place to start in its Civil War Soldiers and Sailors System (CWSS). You can search for Union or Confederate soldiers and African-American Union sailors. Our search turned up a Joseph H. Harbison in the 11th Regiment, Pennsylvania Infantry. Is this your great-grandfather with an incorrect middle initial? Before making the call, you'll want to consult his original service records. CWSS gives you the microfilm number you need to order copies (for a fee) of a service file from the National Archives and Records Administration's (NARA) Order Online site.

In the CWSS search results, click on a unit name for details on when and where the unit was raised and the battles it fought, and how many members died from bullets and disease. Another way to confirm the Joseph we found is your great-grandfather: Check the 1860 US census for the counties where the Pennsylvania 11th was raised for other Joseph Harbisons.

Your great-grandfather may have applied for a military pension. Look for the General Index to Pension Files, 1861-1934, on microfilm at large public libraries, NARA and the Family History Library in Salt Lake City. It's also on the subscription Web site Ancestry.com —I found a Joseph Harbison who filed for a pension in Pennsylvania July 29, 1890 (his application number is 495309). Keep in mind this could be a different Joseph; request copies of the originals from NARA to be sure.

For more information on researching Civil War and other military ancestors, see the October 2005 Family Tree Magazine.