Bell also supported every major piece of Civil Rights legislation considered in the Congress during his tenure, often working at odds with his own party, which frequently opposed these bills, and became a tireless advocate early on for the legislation which eventually became the Civil Rights Act of 1964. As the bill needed substantial bipartisan support from Republicans to gain approval to counteract the opposition of Southern Democrats, Bell contributed significantly to passage of the Civil Rights Act in the House by helping to round up the necessary Republican votes. In this effort, he worked closely with and became close personal friends with Clarence Mitchell, Jr. of the NAACP. He and Mitchell walked side by side during the 1963 March on Washington for Jobs and Freedom with Martin Luther King Jr., and both were honored by being seated behind the podium in front of the Lincoln Memorial as King delivered his famous "I Have a Dream" speech.