What impact did the nazi invasion of poland have on the united states? a. the blockade of american goods reaching poland decreased production in the united states and prolonged the great depression. b. the united states closed its immigration ports to exiled poles in a show of neutrality toward the war. c. polish american citizens marched on washington, dc, requesting congress to take action against the invasion. d. president roosevelt called for a neutrality act that allowed the united states to sell arms to the allied powers.