You don't have to be African American to do African American history or genealogy research. Many White Americans go back a few generations and are surprised by the fact that they have an ancestor of a different race, or that someone related to them once owned slaves. Likewise, DNA projects are revealing that most African-Americans by now have some White DNA.
Besides following census and city directories and military records, here are some other documents to look for:
In 1863 when Black soldiers were recruited to serve the Union side of the Civil War, their services was documented. Look for COMPILED RECORDS FOR THE U.S. COLORED TROOPS which can take you to PENSIONS. These will include a soldier's rank, company, and regiment in the U.S.C Infantry, his pension number, and a death date in some cases. The service records can be extensive starting with enlistment places and dates.
Southerns who lost property in the Civil War sometimes made a claim for reimbursement. Look in THE SOUTHERN CLAIMS COMMISSION files. There are sometimes testimonials of great detail. This would include property owned by free persons who were once slaves.
THE FREEDMAN BANK RECORDS can also be helpful. Because freed slaves were allowed to pick their own name (first and last), and sometimes picked one and changed it again, or siblings took different surnames, and many of the records are not easily linked to a census or other record because many slaves moved, this database may not be useful to the majority. However, once in a while a researcher finds gold. Start by running the more unusual names in your family.