In the late 1930s when war broke out in Europe, production increased in the United States. This created more jobs, which meant that fewer young men were signing up for the Civilian Conservation Corps. After the Japanese attacked Pearl Harbor, the War Department needed to divert attention to the war, and the CCC came to an official end in 1942.
However, prior to this Congress had been considering making the CCC permanent. So what if WW2 hadn't happened - or broke out later than in OTL - and the CCC was made a permanent public force in the US, kind of like the police or fire-fighting services?