The Polish-American anarchist Leon Czolgosz was inspired to by the killing to carry out the assassination of US President William McKinley in Buffalo, New York, September 1901. Despite the fact that Czolgosz had been a native-born citizen, the United States Congress responded by passing a law banning anarchists from immigrating to the United States.
Leon Czolgosz, a Polish-American anarchist, was motivated to assassinate US President William McKinley in Buffalo, New York, in September 1901.  The assassination led to the United States Congress passing a law barring anarchists from entering the country.