I will Pass on Information of web Sites that I use.
We all know of Historic Map Works... Its free and has 2 options one you can pay for and one that is free. The web site goes back to 1866 and allows you to transpose 1860s maps over present day maps.. It shows you all the old housed that existed back in the 1860's then you can over lay a new road map. I use my cell phone and take a picture of my monitor so I don't pay for downloads. I bring these maps with me when I go looking for old foundations and homesteads.
I also sit home and use the satellite option and I am able to pic out old foundations on a 1860 map and the satellite map tells me if the site is a wood, field or built up .. Great Site......
The best # 1 Site is Called Maprika !!!!!!! It allows you to down load old maps from any sites , into your cell phone, then set the known points, and you can go back to the 1600s if need be. If a building existed on a site this maps moves a cursor as you drive and if the points are setup right you can drive up then walk up to that site and the map/icon will put you right on the site... Its a crazy site. I have over 30 maps form the 1830- 1860s and as I drive, I am driving on property, woods even water that existed in the 1850 s then a the map locates a house as it sat in the 1850. It has allowed me to find so many sites and I show the farmers my phone map and as I walk on his land I tell him a house is right here. The icon moves with me ..... I love the site. You have endless detecting opportunities. My maps are 1850 and come from government sites. You can even download maps from 1492 and it will show you driving in woods and fields as they were back then !! The Icon moves as you drive. \
My buddy has a PHD and downloaded my maps for himself. He left the area we switched phones I had a few extra phones. . I have over 30 maps with hundreds of homes, saw mills, churches and schools.....from 1850. Sometimes I must walk 1 or 2 miles in a woods or undriveable road walking with my phone will put me right on the house foundation.. If you are serious about this hobby you need to get acquainted with this site. I am to old school to work the Maprika Sites but I don't need to I have years of detecting w with the maps I have .... Jim