In 1939 he batted .302, led the Senators with 103 runs, and topped the league for the first time with 51 steals, also earning the first of four All-Star selections.

After having 33 stolen bases and leading the AL in assists in 1941, he hit a career-high .320 in 1942, again scoring over 100 runs with 44 steals.

In December 1945, he was traded to the Cleveland Indians for Jeff Heath; in 1946 he won his last stolen base title with 28, though he only batted .225 with just 46 runs.

In March 1947 Case was traded back to the Senators, and after hitting for a .150 average in 36 games he retired due to spinal problems which had plagued him throughout his career.

In retirement, Case opened a sporting goods store in Trenton, and also coached at Rutgers from 1950 to 1960, winning the school's only College World Series berth in his first year.