One of my favorite websites for American research is USGenWeb.org, an all volunteer FREE website for every county in every state in the USA. So, if you know your ancestor was born in a certain state and county, give it a try. Click on the state first to go to that webpage, then click on the county in that state. If you don't know the county but just the city-the STATE website many times has a list. There's always a map and history of the county and sometimes photos also.
Every county webpage is different because each one has a different volunteer webmaster. Some of the fun things they usually include are QUERIES that you can leave and check for your surnames in this area. If there's a SEARCH ENGINE for the county site-be sure to type your ancestor's surname and see what comes up. Check also CEMETERY and CENSUS records, local history, BIOGRAPHIES of early settlers, early NEWSPAPERS, old photos, LOOKUPS etc. Many times there are links that will give you the address of the local County HISTORICAL SOCIETY's Library or the COUNTY COURTHOUSE's address for further researching. It's a marvelous resource for American research.