1823 – Monroe County, Florida’s sixth county was created on this date. It was named after the fifth president of the United States James Monroe. It was during his administration that the U.S. acquired Florida through the Adams-Onis Treaty in 1819. The county covers the chain of islands known as the Florida Keys, as well as a large portion of Florida’s southwestern most mainland area of the Everglades. The majority of the population lives in the Keys. The location of Key West in the middle of the Florida Straits helped the city develop into a major commercial hub in the 19th century. In 1912 the isolated Keys were connected to mainland Florida via the Overseas Railway extension of Henry Flagler’s Florid East Coast Railway. Today, over 76,000 people call Monroe County home.