I only included NY and LA with two teams. Chicago will soon be passed by DFW in metro population and isn't as geographically divided as NY and LA. Parentheses are their MSA population rank.

East
Northeast New York (1), Brooklyn (1), Boston (11), Philadelphia (9)
North Washington (7), Baltimore (22), Toronto (1 Canada-would be 10 US), Montreal (2 Canada-would be 15 US not counting Toronto)
Central Cincinnati (30 but would be 19 with Dayton included), Pittsburg (28), Cleveland (34 but 22 with Akron), Charlotte (21)
Southeast Atlanta (8), Orlando (20), Tampa (17), Miami (6)

West
Midwest Minneapolis (16), Chicago (3), Detroit (14), St. Louis (23)
Plains Houston (5), Dallas (4), San Antonio (24), Denver (19)
Southwest LA (2), Anaheim (2), San Diego (18), Phoenix (10)
Northwest San Francisco (13), Portland (15), Seattle (26), Vancouver (3 Canada but would be 25 US)