You can use this lookup to search RadioQTH's database of call signs. The data is a day or two behind the FCC's data so some calls might have been assigned and yet still show as inactive or not show up here at all. For the latest up-to-date information you can search the FCC's live data by clicking here. For the RadioQTH lookup below, once the results come back you can click on the call sign and get a detailed listing of the call holder's license data. While the call holder's data is showing you can click on the License ID field and get a history of that specific call holder's license.
If you would like to do a more advanced license call sign lookup, where you can list amateur radio operators by their zip code, then please use the Zip Code Lookup feature by clicking here.