Northwestern University has about 8,100 undergraduate students–although the liberal arts school probably enrolls about 2,000 to 3,000. Hard to estimate as anyone can double or triple major in any college/school within the university. Very easy to switch majors if one desires to do so.
Northwestern is located in an upscale suburb of Chicago–Evanston–which is not a college town. Very smart, hard-working, down-to-earth students.
U Penn in Philadelphia is another to consider.
Washington University in St. Louis.
Vanderbilt University in Nashville.
Maybe Tulane University in New Orleans.
Emory in Atlanta.