When did bulldozers first use hydraulics to operate their blades?

Bulldozers began using hydraulic systems to operate their blades in the 1930s. The introduction of hydraulic technology allowed for more efficient and precise control of the blade's movement compared to earlier mechanical systems. This innovation significantly enhanced the performance and versatility of bulldozers in construction and earth-moving applications. Over the years, hydraulic systems have continued to evolve, becoming a standard feature in modern bulldozer designs.