Flagler County is a county located in the U.S. state of Florida. Its county seat is Bunnell. Flagler County was created in 1917 and was named for Henry Morrison Flagler,a famous railroad builder who built the Florida East Coast Railway. Flagler county was the fastest-growing county in the nation from 2000 to 2005. Flagler County has a total area of approximately 571 square miles of which 85% is land and 15% water. As of the 2000 census, there were 49,832 people, 21,294 households, and 15,672 families residing in Flagler County, FL.