The Broer Map Library historic map index is an index of over 100 historic map collections with over 60,000 links and 190,000 keywords. When searching for maps, try multiple variations. For example, try specific placenames, then regional placenames or nearby placenames.
Please note that there is a bug in the search algorythm that blocks some three letter placenames from being found. e.g. a search for ‘Los Angles’ will turn up no results, but searching for ‘Angeles California’ will turn up results for Los Angeles. We are working on this problem.