It's important to remember that place names change over time, so if you are trying to map things within a certain era, you are best off finding a historical map to confirm that if you are trying to map a writer's residence at 15 Elm Street in 1935 that the Elm Street on a current map is the same as the one in 1935.
When you find these historical maps, you may want to create your own map on top of them, and if they are in the public domain or you have permission to do so this can create a nice background presentation for your project, with the added bonus that you'll be able to portray a largely more accurate picture of the area.
Maps from a given era can be very useful to you as a historian, they can help you understand how parcels of land have changed over time, and tell you something about your subjects' lives. If you are studying a geographical area and have found a map that is of the correct time-frame and boundaries to be useful to you, you can take an additional step to add value to it by georeferencing it. Georeferencing is the process of taking what is called a raster (as opposed to vector) image and putting it into geographic space. A raster image can be many different kinds of drawings or photography including satellite imagery, architectural drawings, or in the case we'll be exploring here, a scan of an old map. When this is georeferenced, geographic information such as coordinates is added to it so that by adding features to the map, for example, if you wanted to mark where certain buildings that were meaningful to your project were, you are placing them as a specific point on the globe that you can relate to other data.
With this tutorial you'll take a historical map downloaded from the New York Public Library that shows the original location of Manhattan College and georeference it to a map of the same area today. I'll be attaching the image below, but if you want to find more information about it, it's available at: http://digitalcollections.nypl.org/items/96737d39-3456-fb23-e040-e00a18067dcb
You add georeferencing to a raster item by adding anchor points to the item and to the map beneath it where the two share a common location. When you add enough of these, ArcGIS will be able to rectify the two items, and accurately stretch and place the raster item over the locations on the basemap that it covers.
Whenever you add a layer with information to your map, you'll want to also add additional data about where you got that information so that your viewers will know where it came from.This data about data is called 'metadata'.
New York Public Library
since that is where you got the information
For the description, go to the address in the introduction for where this book was located on the New York Public Library's website: https://digitalcollections.nypl.org/items/96737d39-3456-fb23-e040-e00a18067dcb and on that page choose Cite This Item.
Lionel Pincus and Princess Firyal Map Division, The New York Public Library. (1884-). Manhattan, V. 11, Plate No. 3 [Map bounded by Broadway, W. 133rd St., Amsterdam Ave., W. 130th St.] Retrieved from http://digitalcollections.nypl.org/items/96737d39-3456-fb23-e040-e00a18067dcb
When you are done, save your map. You can see how mine came out if you look at the below.
You can further customize a map by adding your own features to it, creating your own feature class. Similar to how you may have downloaded shapefiles that depict where certain landmarks or facilities are from say, Open Data NYC, you can create your own file called a feature class where you mark with points or polygons the locations important to your research. You can store all of these items within something called a geodatabase that packages all your data for a given project together.
With this exercise, you'll create features what was on the blocks surrounding Manhattan College in its former location. You'll create and edit a feature class of this area, by referring a georeferenced map created from old maps of the area layered over the current maps, and add labels for your new shapes. Then you'll save all relevant files into a geodatabase so other users can look at the items you created if they want to expand your project.
Now that you've created a feature class to use to trace the outlines of Manhattan College and other buildings around it, you'll need to add features to it.
When you've added a bunch of shapes to your map for buildings you'd be interested in superimposing on today's map, move onto the next step and change the symbology of the tabs to reflect their purpose.
You can proceed from the map that you created but if you want to follow along with the categories for purposes that I created, it is below.
You've now created a labeled map with edited features. If you want to see how I constructed mine, it will be in the attachment below.