The best institute in the United States to learn about archaeology is a matter of opinion or interpreting how the rankings line up. Just because one experts says one institute is the best doesn't make it so. One institute might lead accademicwise but flunk out when their graduates try to actually work in the field. That having been said, my view of the best Anthropology College in the U.S. is Washington University in St Louis, handsdown.
Others that come in closely behind are Columbia University in New York. City New York. and the infamous Yale University which is highly accredited. Honorable mentions are the University of Michigan and the University of California located in Los Angeles as well as the University of California in Riverside, California. All are excellent institutes to learn in.