A new educational system was established with English as the medium of instruction, eventually becoming a "lingua franca" of the Islands. The 1920s saw alternating periods of cooperation and confrontation with American governors-general, depending on how intent the incumbent was on exercising his powers vis-à-vis the Philippine legislature. Members to the elected legislature lobbied for immediate and complete independence from the United States. Several independence missions were sent to Washington, D.C. A civil service was formed and was gradually taken over by Filipinos, who had effectively gained control by 1918.