Historic Aerials claims to be “Home of the most comprehensive database of historical aerial photos of the United States.” Indeed, it is a huge resource.
According to information on the Historic Aerials web site:
“Take a ride in our time machine!
“Nationwide Environmental Title Research has spent the past 20+ years collecting the worlds largest database of historical aerial images and topographical maps of the United States. Our sources include USGS imagery, several private collections, and we are continually acquiring more. All the imagery we collect is painstakingly orthorectified to provide the data in a searchable and precise geo-locatable format. Our web application allows you to quickly and easily search for any parcel of U.S. land and instantly view that same area in any other year where we could obtain an aerial photo.”
While the basic service is free, the pictures displayed to free users have a rather obnoxious watermark pasted on top of each image. That makes the free images almost useless. Obviously, the web site owners want each user to sign up for a paid account in order to obtain more useful images.