Henry Flagler, a wealthy industrialist and travel entrepreneur, and his ailing wife had recently relocated from New York City to Jacksonville, Florida. His wife had been diagnosed with consumption, so doctors urged him to take her away from the harsh New York City winter to a warmer area. However, his wife died shortly after the move.

Henry found a new wife and relocated to St. Augustine, Florida. The man of action that he was, he realized the potential of the sleepy town as a major tourist destination. Yet, there were hardly any places to stay in the region. He went looking for a suitable location on which to construct the Ponce de Leon, an opulent hotel.

He zeroed in on a spot that looked out over the county jail. In 1890, the St. John County jail was an eyesore. Henry gave $10,000 to the St. John County Commissioners to get rid of the old structure.

In response, the prison was relocated several blocks away. They had a large construction budget, so they contracted with The Pauly Company to create the new prison. This was the same skilled crew that would later construct Alcatraz.

Flagler carefully considered how this fortification's exterior would affect the Old City's aristocratic atmosphere. To this end, it was built in the Romanesque Revival style, which gives it the recognizable appearance of a Victorian mansion. Barricades on the windows were the only giveaway that this building housed incarcerated people.

Until 1953, the jail provided services to the city of St. Augustine. Some of the county’s most dangerous criminals were housed there, and the facility's gallows were frequently used for public executions.

The jail was turned into a tourist attraction in 1954, just one year after it had closed its doors. The new owner, Henry L. "Slim" McDaniel, decided to renovate it in 1993. The Old Prison in St. Augustine is now open to the public, giving tourists a glimpse into the city's legal history and the daily lives of those incarcerated there. The US National Park Service began preserving the Old St. Augustine Prison as a historic site in 1987.