The Mexico City National Cemetery was established in 1851 by Congress to gather the American dead of the Mexican-American War (1846-1848) that lay in the nearby fields and to provide burial space for Americans that died in the vicinity. The remains were gathered in 1851 and buried in a common grave at this cemetery. They were not identified so they are classified as unknown soldiers. A small monument marks the common grave of 750 unidentified American dead of the War of 1847. 
In this one-acre area are also placed the remains of 813 Americans and others in wall crypts on either side of the cemetery. The cemetery was closed to further burials in 1923.
