Dade County, Florida 1870 Federal Census Notes from transcriber: Sandra Willis Wm. S. Allen took the 1870 Federal Census for Dade County on the 30th of July and The 1st of August. In 1870 Dade County covered most all of present-day Palm Beach, Broward, Dade, and Monroe Counties. It did not include the string of Keys leading to Key West as it had in 1860. It is hard to believe that in all those square miles that there were only 86 people.