Early years

Clark attended Taylor High School. He accepted a scholarship from Northwestern University where he played as a cornerback. In 1966, he received All-American and All-Big Ten honors. He also played in the 1967 Chicago College All-Star Game.

Professional career

Dallas Cowboys

The Dallas Cowboys started the 1967 NFL Draft without a first and second round draft choice, that were traded as part of the price to solve the Ralph Neely dispute with the Houston Oilers. Clark was selected in the third round (76th overall).

After being a reserve in his first 2 years, he was named the starter at right cornerback in 1969. That season he started in 12 games, before being benched in favor of Otto Brown.

On January 27, 1970, he was traded along with Craig Baynham to the Chicago Bears in exchange for a second round draft choice (used to draft Bob Asher).

Chicago Bears

The Chicago Bears switched him to strong safety, where he earned the starter position. He was released before the start of the 1971 season.

New England Patriots

After his release, he signed as a free agent with the New England Patriots. He was released on October 7, 1971, after playing in just two games.

[ Source: Wikipedia ]