Maps are very important in genealogical research. They can give you many clues to assist you. In addition to seeing where your ancestors lived, you can see bordering towns and counties, and even states. Topgraphic maps can provide clues to your ancestors’ migration, by showing how natural routes may have been followed (up or down rivers, around mountains, etc.).  They can even reveal man-made routes, such as roads or canals, that may have been migration routes for your family.

One of the largest online collections of maps is available through the Perry-Casteñeda Collection at the University of Texas at Austin. The university is working to digitize this large collection and make it available online for free to all users.

The online maps are divided into geographic categories: World, Africa, Americas, Asia, Australia/Pacific, Europe, Middle East, Polar/Oceans, Russia/Republics, U.S., Texas, Texas Counties, and Austin. When you click on one of the major categories, you will come to a page with further groupings of maps for that category. For example, under United States you will find, among others, the following:

• Maps of the United States
• Historical Maps of the United States
• National Atlas of the United States (1970)
• National Parks, Monuments, and Historic Sites Maps
• State Map Collections
• State Maps with County Boundaries
• Topographic Maps
• U.S. Territories Maps

I looked to see what maps they might have of Boston, and found some very interesting ones. Several maps came from a published 1886 report from the U.S. Census Office on social statistics.

1772 map of Boston by Capt. John Bonner overlaid with the streets as they appeared in 1880.

The above map shows a 1772 map of Boston by Captain John Bonner, overlayed with the streets of the city as they appeared in 1880. You can see the original boundaries of the peninsula, and how much landfill was used to create new sections of the city.

Original boundaries of towns annexed to Boston in the 19th century.

The above maps shows the city of Boston in 1880, with the original bounds of towns that were annexed in the nineteenth century. Allston, Brighton, Charlestown, Dorchester, East Boston, Roxbury and West Roxbury were all annexed to the original territory.

The site also provides access to a number of tools for use with maps: distance calculators, gazetteer, glossaries and guides, map scales, and more. You will also find copious links to other sites of cartographic interest. The Perry-Casteñeda Collection has currently digitized tens of thousands of maps and made them available. This is only a fraction of the more than 250,000 maps in the entire collection. It is continuing to raise funds to acquire and digitize and even more maps. If you use the site and find it useful, consider visiting the Support Us section and making a donation to help them in this process.