In this time period, the common term used for African Americans was “colored.” While this term is no longer used, searching it in historical databases may yield more relevant primary resources.
When searching for a particular organization or individual, you may need to put quotation marks around the name, depending on the database you are searching. For example, searching “Political Equality League” will often search for this exact term as opposed to Political Equality League, which will expand your search to include items with any or all of the words.
When searching for particular women, remember that during this time period, most women went by Miss if they were not married or Mrs. In the latter case, they may have used Mrs. with their own name or Mrs. with their husband’s name. This means that you can search for “Carrie Horton” or “Mrs. Carrie Horton” but that you should also search for “Oscar Horton” or “Mrs. Oscar Horton” if you know the husband’s name. This may yield results you didn’t get from only searching the woman’s name.