Complex sentence: Quota restrictions on immigration to the United States were also loosened, allowing many Holocaust survivors to immigrate to the United States where they were provided with US immigration visas for displaced persons under the Displaced Persons Act.
Split into simpler sentences: Quota restrictions on immigration to the United States were also loosened, allowing many Holocaust survivors to immigrate to the United States. Immigrants were provided with US immigration visas for displaced persons under the Displaced Persons Act.