USGS has a vast database of images including aerial, weather satellites, declassified reconnaissance satellites, and other sources.

https://earthexplorer.usgs.gov/

The datasets you pick from can be a bit confusing unless you click the (!) icon next to the names to figure out what they are.

I'll provide an example for looking at reconnaissance satellite images of Atlanta, Georgia in 1979.

Search Criteria (tab):

Find Atlanta, Georgia on map. Zoom in on Atlanta, Georgia. Click on a building like the "Fulton County Courthouse" or "Atlanta City Hall" (does not really matter, but somewhere near them).

Date Range: 01/01/1970 - 01/01/1980

Data Sets (tab):

Declassified Data -> [check] Declass 3 (2013)

Click "Results".

Click one of the results.

Example image: May 15, 1979 - https://i.imgur.com/DXYxWXP.jpg - 14,273 x 1,414 px