A complex of mounds west of Boynton Beach, near the Loxahatchee National Wildlife Refuge, has yielded pottery possibly from 150 BCE and beads and glass from as late as the 16th century. Captain James A. Armour, head keeper of the Jupiter Inlet Lighthouse, filed the first land claim here in 1875, though he probably never lived on it. Dexter Hubel of Michigan and his family arrived two years later and stayed at the Orange Grove House of Refuge until their house was built.
More about Boynton Beach
In 1894 Major Nathan Boynton, a Civil War veteran from Port Huron, Michigan, saw the area and built the Boynton Hotel, which opened in 1897 with room for 100 guests and lasted until 1925. The first post office opened in 1896. Settlers grew pineapples, tomatoes, mangoes and citrus for shipment north on the Florida East Coast Railroad, and two African American farmers, Alonzo King and Samuel Cade, taught them how to farm the muck soil.
The town was founded on September 26, 1898, when Byrd Spilman Dewey and her husband Fred S. Dewey, one of Flagler's secretaries, filed the plat for the Town of Boynton. By 1900 the town had 83 people and a new schoolhouse on Ocean Avenue.
Sources
Wikipedia: Boynton Beach, Florida
The Historical Marker Database: 1913 Boynton Elementary School; Boynton Woman's Club