Mr. Trump began his presidency by signing an executive order that sought to limit travelers from seven largely Muslim countries for 90 days.
The order, with some exceptions, affected travelers from Iran, Iraq, Libya, Somalia, Sudan, Syria, and Yemen.
Advocates sued, and the case went to the Supreme Court, which upheld the policy in a 2018 ruling.
The Border WallIn 2017, Mr. Trump began focusing on one of his earliest campaign promises — building a physical wall along the border between the United States and Mexico.
The idea was initially suggested by a Trump campaign aide, Sam Nunberg, as a memory aid to prompt the candidate to remember to talk about immigration in his speeches.