Hamilton was born in Dedham and raised in Newton, Massachusetts, the son of Roger S. Hamilton, once the Dean of Northeastern University. He graduated from Newton High School in 1960. His racing roots began at Norwood Arena Speedway in Massachusetts in 1962, where he earned the "Dedham Flash" nickname for his aggressive style. Hamilton won the 1965 Thompson World Series Twin 50s championship and the 1967 NASCAR national Sportsman division championship, establishing himself as one of New England's premier short-track talents before making the move south.
Hamilton entered the NASCAR Grand National division in 1968 and was named the series Rookie of the Year. In 1969, he competed primarily in NASCAR's Grand American division — a series for smaller pony cars — winning 12 of 26 races and demonstrating versatility across vehicle classes. That same year, however, a crash in a Grand American race left him with a neck injury that would ultimately define the boundaries of his career.
His breakthrough at the top level came in 1970 with Petty Enterprises, driving the No. 40 Plymouth Superbird with Maurice Petty as crew chief. Hamilton won three races that season: the Daytona 500 and both events at Talladega Superspeedway. Winning at Daytona and sweeping Talladega in the same year placed Hamilton among the elite performers of the superspeedway era, even if he ran only a partial schedule.
In 1971, Hamilton drove Cotton Owens' No. 6 Plymouth and won his Twin 125 qualifying race for the Daytona 500, finishing the season with one pole and eleven top-five finishes. He continued racing until 1973, when complications from his 1969 neck injury forced him to retire from full-time NASCAR competition. Hamilton also won the 1974 Snowball Derby in his late model racecar, showing his short-track instincts remained sharp after leaving the Cup circuit.
After stepping away from driving, Hamilton contributed to the sport in a different capacity. He helped Chrysler engineer Larry Rathgeb develop the "Kit-Car" — a weld-it-yourself Volare or Aspen late model stock car that could be ordered from Plymouth and Dodge dealers, democratizing competitive racing for grassroots teams. Working out of Norcross, Georgia, he became a car builder and mentor on the 1980s southern dirt tracks, helping launch the careers of Marvin Oliver and James Shepherd.
Hamilton was inducted into the New England Auto Racers Hall of Fame in 1998 as part of its inaugural class, and into the Georgia Racing Hall of Fame in 2012 — a fitting recognition of a driver who bridged the New England short-track world and the upper reaches of NASCAR's superspeedway circuit.
Hamilton died on March 21, 2017, at age 74, from complications of a stroke. He was survived by his wife of forty-seven years and a daughter, and was buried at Peachtree Memorial Park in Norcross, Georgia.