I'm not sure how "Plat" maps got their name.
(If any of my readers know the answer to that, please leave a comment!)
Plat maps are maps that often feature the property lines of farms or rural areas, areas that may now be cities or suburbs. In a way they are like zoning maps today.
Plat maps have the names of the owners of that land on a specific year and can tell you so much about the early settlers of an area, and lead you to more information such as who got Land Grants, names to search for in early wills and land sales, etc.
Something that can be a fun early genealogy research lesson for kids is to find the Plat map for where you live now and see how many of the roads, lakes, and other geographical features bear the names of those early settlers say right before and after the Civil War.
I like the big old fashioned maps that have been replaced by digitalized editions on the internet as I find them far easier to read, but if you live far away from a library that houses the big maps this is a good option. Locally, you might find that a historical society or university library has a collection that you can use without being a member or student.
After the American Revolution, many soldiers who fought for little or no pay and lived were rewarded with land. These are called "Reparation Lands." Not exactly "40 acres and a mule" but something like that.
Looking at the same area before and after the Civil War is also an interesting history lesson.
