It was a system of mutual and reciprocal aid which gave the U.S. about $ billion of services (especially rental of military bases on Allied soil). More broadly it meant the pooling of the resources, the man power, and the inventive genius of every Allied power. Though the United States initiated the action through the Lend-Lease Act of March 11, 1941, and though it furnished by far the largest contribution measured by monetary standards, lend-lease was a two-way affair, each nation giving to the common cause according to its resources.