Somewhere in the early 20th century, the federal government started taking a more active role in timberland management and the control of wildfires. In 1935, President Franklin Delano Roosevelt initated a massive widlfire control public works camapign, with the aid of a few Disney characters and Smokey the Bear. The government has assisted in the fighting of wildfire breakouts and in the removal of debris by conducting what are known as controlled burns. In a controlled burn, underbrush and smaller trees are burned away a section at a time, so as to remove the fuel that would sponsor an out-of-control wildfire. The policy shift has swayed back and forth over the successice adminsitrations that have been elected to office. Controlled burns have largely been proven effective at reducing wildfires and containing them once they do start. Controlled burns also greatly reduce insect infestation and remove rotting vegetation that promotes insect iniated disease.