Which factor Caused the Irish immigrants to come to the United States in the 19th century a chance to buy huge pots of American land be the collapse of the Irish potato crops due to disease see US policies that promote a Catholic immigration the a growing demand for farm labor in the American south

explanation:

there are two statements that are incorrect.

1. the marshall plan was a lend lease program. it was an economic plan that europe redevelop itself after wwii.

2. einstein didn't really do anything to further the allied cause in building the bomb. he merely sent a letter to fdr telling him (in 1939) that if the united states entered the war, perhaps it would be wise to build the bomb before germany did. i would say this answer is incorrect, but when america entered the war 2 years later, fdr thought it might be a good idea to take einstein's advice.

the 4th choice is definitely so wrong that is likely the single answer of this question

it granted civil rights to african americans.

trumans defeat to eisenhower in the 1948 elections was due to trumans approach and handling of the cold war and the war in korea. trumans approach to communism during the cold war was the principle reason for his defeat. eisenhowers reputation and name as the supreme allied commander in europe during world war two and his campaign slogan that he ''would go to korea if elected'' won him the presidency.