The United States Geological Survey has nearly completed its project to digitize over 200,000 topographical maps and create a free, searchable online archive. The project began in 2009 and aims to preserve and improve access to these valuable historical maps, some of which were only available in the USGS archive in Virginia. So far, the USGS has digitized its entire collection of the contiguous United States and Hawaii, and plans to release the remaining maps for Alaska, Puerto Rico, the Virgin Islands, and Trust Territories between now and September of this year. If you've ever wondered what your city looked like nearly a century ago, now's your chance — you can search the archives and download hi-res images of the maps for free from the project's site.