Trump is correct
US immigration legislation online
1952 Immigration and Nationality Act, a.k.a. the McCarran-Walter Act (An act to revise the laws relating to immigration, naturalization, and nationality; and for other purposes)
H.R. 13342; Pub.L. 414; 182 Stat. 66.
82nd Congress; June 27, 1952.
You can find the full text of this law here or download the PDF.