Templeton began drawing when he was about 11 years old and recalled how he looked forward to the arrival of The Saturday Evening Post with the cover painting by Norman Rockwell, which contributed to his decision to become an artist.

In the summer of 1949 Templeton traveled to Santa Fe, New Mexico, to visit with the artist John French Sloan and his wife Helen.

[citation needed] With a letter of recommendation from John Sloan, Templeton was able to get a Ball Grant from the Art Students League two years in a row.

During basic training at Fort Leonard Wood he painted a forty-foot mural Portrait of America, which showed the influence of Benton.

While still in the army, Templeton met and married his wife Leonore, and upon discharge in 1954, they settled in New York City, where he shared a studio on the Lower East Side.

Inspired by the newly constructed superhighway system covering the Midwest, he devoted his energy to creating works with a transportation age theme.

The Connecticut period was filled with commissions of leaders in government, industry and entertainment, among them presidents Lyndon Johnson and Jimmy Carter,[4][5] First Lady Rosalynn Carter, Vice President Hubert Humphrey, author William Styron, baseball player Stan Musial, poet Carl Sandburg, former Texas Governor John Connally, and opera singers Luciano Pavarotti and Joan Sutherland.

Templeton recorded the chaos in his sketchbook, observing looting, fighting National Guardsmen, firefighters battling blazes, and even the governor's press conference.

[6][7] In 1971, Templeton was commissioned by CBS News to be the courtroom artist for the New Haven murder trial of Bobby Seale, founder of the Black Panther Party.

For nearly twenty years he arranged portrait sittings with leaders in the movement with the help and advice of Dr. Benjamin Mays, mentor and friend of Martin Luther King Jr.

Images of the Black Civil Rights Movement" came out of a conversation Templeton had with Dr. Mays,[10] who worried that so many people, their work and sacrifice, might be forgotten someday.