USGS Historical Topographic Map Explorer
"The federal agency has launched a new map tool that lets users overlay old and new maps, comparing how the city has developed—and in Boston’s case, physically expanded—over the years.
To play with the map, follow this link and enter the location you want to explore in the search box on the left of the page (We’ve already set it to Boston because, honestly, that’s where you want to start, right?). Click on the map once, and a menu of available historical maps appears below.
Select a map and then use the slider that appears on the left to increase or decrease the overlay’s transparency.
Seriously, it’s easier than it sounds. Just go to the USGS site and try it yourself.
Alas, the earliest map used for Boston dates back to 1893, some 263 years after the city was founded. That’s well after the city used landfill in places like the Back Bay (the body of water) to create the Back Bay (the neighborhood where you can’t afford to live)." Boston.com 7/2/14
