The 1919 Florida Keys hurricane (also known as the 1919 Key West hurricane) was a massive and damaging tropical cyclone that swept across areas of the northern Caribbean Sea and the United States Gulf Coast in September 1919. Remaining an intense Atlantic hurricane throughout much of its existence, the storm's slow-movement and sheer size prolonged and enlarged the scope of the hurricane's effects, making it one of the deadliest hurricanes in United States history. Impacts were largely concentrated around the Florida Keys and South Texas areas, though lesser but nonetheless significant effects were felt in Cuba and other areas of the United States Gulf Coast. The hurricanes peak strength in Dry Tortugas in the lower Florida keys, also made it one of the most powerful Atlantic hurricanes to make landfall in the United States. The hurricane developed near the Leeward Islands as a tropical depression on September 2 and gradually gained in strength as it tracked on a generally west-northwesterly path, crossing the Mona Passage and moving across the Bahamas. On September 7, the storm reached hurricane intensity over the eastern Bahamas. On September 9–10, the storm made its eponymous pass of the Florida Keys, passing over the Dry Tortugas with an intensity equivalent to that of a modern-day Category 4 hurricane. Over the next several days, the intense cyclone traversed the Gulf of Mexico, fluctuating in strength before making landfall near Texas' Baffin Bay on September 14 as a large Category 3 hurricane. As it tracked further inland, land interaction caused the storm to gradually weaken; the storm was last noted on September 16 over West Texas. Meteorological history Based on isolated observations east of the Lesser Antilles on September 1, the precursor to the 1919 Florida Keys hurricane may have been a disorganized tropical wave that tracked westward towards the Leeward Islands. The next day, additional observations indicated that the disturbance had acquired a cyclonic circulation; thus, the system was determined to have become a tropical depression by 12:00 UTC that day just east of Guadeloupe. Gradual strengthening occurred as the depression tracked west-northwest, attaining tropical storm intensity at 06:00 UTC on September 3. Twelve hours later, the tropical cyclone clipped the extreme-southwestern portion of Puerto Rico with maximum sustained winds of 50 mph (80 km/h). The cyclone maintained a low-end tropical storm intensity as it paralleled the northern coast of Hispaniola the following day. On September 6,