<Tr> <Td> </Td> <Td> This section needs expansion . You can help by adding to it . (February 2014) </Td> </Tr> <P> There have been various law changes over the years that encouraged immigrants to enter or exit the United States . With the railroad, World War II, and agricultural work force demands, many immigrants saw the opportunity to come to the United States temporarily for money or a better life . An increase in legal immigrants migrating to the United States also led to an increase of illegal aliens, especially from Mexico . Most of these immigrants searched for and gained jobs where hard labor was needed . As the immigration population increased American citizens started to worry about their impact on the economy . </P> <P> The reform did not have a lot of impact on decreasing the immigrant population, "Until 2012, there was virtually no movement in Congress to deal with the problem of the 11 million undocumented immigrants living in the United States since the passage of the Immigration Reform and Control Act of 1986, which granted amnesty to many of the 3.2 million illegal immigrants living in the United States ." </P> <P> "In 1983, the Supreme Court forbade schools and hospitals to deny services based on undocumented immigration status ." </P>

Which act granted a pardon to undocumented immigrants already living in the united states