"All aliens over 16 years of age who are physically capable of reading, except as specified in the statues and described in subdivision 5 of this rule, shall be required to demonstrate their ability to read matter printed in plainly legible type and in a language or dialect disgnated by the alien at the time of examination." (1)
Although attempts had been made to restrict the rights of immigrants prior to the Civil War, starting with the Alien Enemies Act in 1798, efforts to construct a national immigration policy did not begin until the 1870s. (2)
In fact, 1875 marked the first time Congress attempted to bar a specific group of people, prostitutes and criminals, from entering the country. This act was followed in 1882 by the restrictions against the insane and disabled, and finally against Chinese and Japanese laborers. Perhaps the most controversial legislative action, though, came in 1897, when Congress proposed a literacy law, requiring all immigrants to demonstrate their ability to read or write in some language before being admitted into the country. These tests were vetoed by no less than three presidents, including Cleveland, Taft, and Wilson, but were finally signed into law in 1917. (3) This particular act is a topic of much debate in the newspapers within the collection, with many more farmers coming down on the side of the illiterate immigrant.
You can try searching for specific legislation, but it is best to keep your searches simple. For example, instead of the keyword Immigration Act, which will only return a few results, try literacy test or education test, and instead of Chinese Exclusion Act or Gentleman's Agreement, try combining terms used for immigrant with Chinese or Japanese into a single phrase.
(1) U.S. Congress, Act of February 5, 1917: rules of May 1, 1917 (Washington: G.P.O., 1917), http://pds.lib.harvard.edu/pds/view/7566813 (accessed October 26, 2009).
(2) Immigration and Asylum from 1900 to Present, s.v. "U.S. Immigration," http://www.library.uiuc.edu/proxy/go.php?url=http://www.credoreference.com/entry/abcmigrate/u_s_immigration/0 (accessed October 26, 2009).
(3) Immigration and Asylum from 1900 to Present, s.v. "U.S. Immigration Legislation: Pre-1945," http://www.library.uiuc.edu/proxy/go.php?url=http://www.credoreference.com/entry/abcmigrate/u_s_immigration_legislation_pre_1945 (accessed October 26, 2009).