Which significant change occurred in the Marine Corps under General Pate?

The establishment of the position of Sergeant Major of the Marine Corps under General Pate represents a significant change because it formalized the role of the senior enlisted advisor to the Commandant. This position was created to enhance enlisted representation at the highest levels of leadership, allowing for better communication of enlisted issues and concerns. Prior to this, the perspectives and experiences of enlisted personnel were not as effectively integrated into decision-making processes. The creation of this role has since played a crucial part in establishing a stronger link between the enlisted ranks and the command structure, thereby influencing policies and practices that affect Marines at all levels.

In contrast, while the other options represent noteworthy elements in Marine Corps history, they do not directly pertain to a change initiated during General Pate's tenure. The adoption of the Mameluke sword dates back to earlier in Marine Corps history, the terms for Commandants were not lengthened during his time, nor was there a significant change in uniforms that aligns specifically with his leadership period.