William Rex Mercer, 90, of Lake Wales, passed from this life peacefully at home early Thursday morning, July 10, 2025, with his loving daughter and dedicated son by his side.  

Rex was born to the late Ruby Mae Mendheim and George Benton Mercer on April 20, 1935, in Dothan — or “L.A.” for Lower Alabama, as he liked to say with a grin. The second of five children in a family of tenacious sharecroppers who farmed and picked cotton, Rex learned the value of hard work and perseverance at a young age.

After graduating from Ashford High School, Rex enlisted in the U.S. Army at 18. With a firm belief in the power of education and help from the Korean Conflict GI Bill, he attended Southeastern Bible College, where he met his future wife, the beautiful Betty Ann.

Rex earned his Bachelor of Arts degree from Florida Southern College while working as a Lakeland city bus driver. He embarked on a career in education, and while teaching history at Lakeland Senior High and helping raise two young children, he also worked for the Tampa Tribune. During this busy period, Rex commuted from Lakeland to Rollins College in Winter Park to earn his Master of Education degree — later completing his Specialist in Education there as well.

In 1972, Rex was named Principal of Frostproof High School. Three years later, he and Betty Ann moved to Lake Wales, where he served as Principal of Lake Wales High School for a decade, a job he thoroughly enjoyed. There, he helped establish a strong academic foundation and developed a robust athletic program for the Highlanders. He was known as a fair but firm leader who wore his authority well. Though sometimes feared, he was deeply respected and quick to offer guidance or a word of encouragement, frequently telling his students how proud he was of them. He also taught night school English classes, encouraging students to earn their diplomas or GED certificates.

After his tenure at Lake Wales High, Rex became Director of Transportation for Polk County Schools, a role for which he was also well-suited. Upon retiring from the school system, he earned his real estate license and concluded his working life with Music Realty.

Those who knew Rex will remember his formidable presence as well as his warmth, generosity, and love of storytelling. He rarely kept conversations short, and was often inquisitive, entertaining, and larger than life. He had a sharp mind, a big heart, a good sense of humor, and a genuine love for people and their well-being. Always ready to help, he looked out for others and believed that everyone deserved a chance to better themselves.

An ordained minister and man of deep faith, Rex was a longtime member of First Assembly of God (now Impact Church), where he served as Chair of the Deacon Board. He played a key role in facilitating the challenging and hard-won purchase of the church property at the entrance to Bok Tower Gardens — where the church still stands nearly 40 years later. His integrity, leadership, and resolve left a lasting impression on his family, students, colleagues, church members, and many others throughout Lake Wales, the Polk County community, and beyond.

After just two weeks apart, Rex joined his beloved wife, Betty Ann – together again in eternal peace. He was preceded in death by his brothers, James Maxwell and George Wayne Mercer, and his sisters, twins Carolyn Annette Pelham and Marilyn Jeanette Kabrich.

He is survived by his children — his warmhearted daughter, Lanna Mercer Barbaroux, and her partner, Eduardo Beltran, both of Austin, Texas, as well as his devoted son, William Steven Mercer, who lovingly cared for his parents in their final years.

A joint Celebration of Life for Betty Ann and Rex will be held on Saturday, August 23—what would have been their 67th wedding anniversary—at Impact Church, 1201 Burns Avenue, Lake Wales. A tribute video will begin at 1:30 p.m., followed by the service at 2:00 p.m. Friends, family, former students and colleagues, and all whose lives they touched are warmly invited to gather, share memories, and celebrate the enduring legacy of this remarkable couple’s life of service, faith, and love.