Like an addendum, a contract amendment is also an addition to a contract or agreement. An amendment, however, is generally not used to add terms and conditions, but rather to change existing terms and conditions.
Constitution of the United States.
Fourteenth Amendment, Section 1: All persons born or naturalized in the United States, and subject to the jurisdiction thereof, are citizens of the United States and of the State wherein they reside.
14th Amendment to the U.S. Constitution: Civil Rights (1868) Citation: The House Joint Resolution Proposing the 14th Amendment to the Constitution, June 16, 1866; Enrolled Acts and Resolutions of Congress, 1789-1999; General Records of the United States Government; Record Group 11; National Archives.
Constitution of the United States.