On 27 March 1941, the number of lend-lease ships was increased to 200 by the Defense Aid Supplemental Appropriations Act and increased again in April to 306, of which 117 would be Liberty ships.
1941年，3月27日，防御援助辅助拨款法案通过，租借法案船只增加到了200艘，并且在四月增长到306艘，其中117艘就是自由轮。