There are numerous sources setting out what documents are required for entry into the U.S., for U.S. citizens and for non-citizens, by air, land or sea. The USCBP has set out a short overview of what documents are required for foreign nationals or U.S. green card holders, at the link set out below.

USCBP's "What documents does a foreign national or green card holder need to enter the U.S.?"