I thought this would be helpful to post for our International Brothers, and American ones looking to travel in the US.
Hell, I didn't know most of these (I bolded some places of note and added some comments in parentheses) :
City-specific laws
Albany, New York: 4 a.m. (Who knew?)
Atlanta: 2:30 a.m.; 4:00 a.m. in Underground Atlanta. Midnight on Sunday night/Monday morning. (What the f*ck is "Underground Atlanta"?)
Atlantic City, New Jersey: 24 hours.
Austin: 2 a.m.
Baltimore: 2 a.m.
Bloomington and Normal, Illinois: 1 a.m. on weeknights, 2 a.m. on weekends.
Bloomington, Indiana: 3 a.m.
Boston: 2 a.m. (lame)
Buffalo: 4 a.m., 24 hours on specific holidays. (surprising)
Champaign, Illinois: 2 a.m.
Charlotte: 2 a.m.
Chicago: Some bars may choose to close at 2 a.m. or earlier. They may alternately get an extension which allows them to close at 4 a.m. or earlier. On Saturdays, closing times are shifted an hour back to 3 and 5 a.m.
Cincinnati: 2:15 a.m. for last call; 2:30 a.m. for closing time.
Cleveland: 2:30 a.m.
Columbus: 2:30 a.m.
Denver: 2 a.m.
Florence, South Carolina: 2 a.m. for hard liquor, 3 a.m. for beer. This includes Sundays where any bar that is defined as a private club may operate 7 days a week, otherwise last call is midnight Saturday night, until the establishment reopens for business on Monday.
Fort Wayne, Indiana: 3 a.m.
Houston: alcohol service stops at 2:00 a.m.
Indianapolis: 3 a.m.
Kansas City, Missouri: 1:30 a.m. for most bars, 3:00 a.m. for specially licensed bars in certain geographic areas. 6:00 a.m. for one bar only, the Mutual Musicians Foundation. (Whoever owns that bar is sitting on a goldmine).
Las Vegas, Nevada: Bars may stay open 24 hours a day, 7 days a week.
Los Angeles: 2 a.m. (more like 1:30am, weak)
Lexington, Kentucky: 2:30 a.m.
Louisville: 4 a.m.
Miami: 5 a.m.; Bars may stay open 24 hours, 7 days a week in the Downtown Entertainment District.
Minneapolis / Saint Paul: 2 a.m.
Mobile: No last call for bars operating under a private club license
New Orleans: Bars may stay open 24 hours, 7 days a week.
New York City: 4 a.m., nightclubs are permitted to stay open after 4 a.m. but cannot serve alcohol.
Pensacola, Florida: 3 a.m. (within city limits, 2 a.m. for county)
Peoria, Illinois: Bars in the downtown district may stay open until 4 a.m. Bars in other areas may stay open until 1 a.m. Sunday through Wednesday and 2 a.m. Thursday through Saturday. Bars may stay open 2 hours later than normal closing hours on New Year's Eve, providing additional patrons are not allowed after normal closing hours.[14]
Phoenix / Scottsdale: 2 a.m.
Philadelphia: 2 a.m.
Pittsburgh: 2 a.m.
Providence: 2 a.m. on weekends, 1 a.m. on weeknights.
Rochester, New York: 2 a.m.
Salt Lake City: 1 a.m.
San Diego: 2 a.m. (more like 1:30am, weak)
San Francisco: 2 a.m. (more like 1:30am, weak, although SF places are known to break rules, thank God.)
Savannah, Georgia: 3 a.m.
Seattle, Washington: 2 a.m.
Shreveport, Louisiana: 6 a.m. for Downtown, 2 a.m. everywhere else.
St. Louis: 2 a.m. on Weeknights, 3 a.m. on weekends.
St. Petersburg: 3 a.m.
Tampa: 3 a.m. (not bad)
Washington, D.C.: 3 a.m. on Friday night, Saturday night, and the night before a federal or DC holiday; 4 a.m. on the night of New Year's Eve; 2 a.m. other nights.[15]
http://en.wikipedia.org/wiki/Last_call_(bar_term)
Hell, I didn't know most of these (I bolded some places of note and added some comments in parentheses) :
City-specific laws
Albany, New York: 4 a.m. (Who knew?)
Atlanta: 2:30 a.m.; 4:00 a.m. in Underground Atlanta. Midnight on Sunday night/Monday morning. (What the f*ck is "Underground Atlanta"?)
Atlantic City, New Jersey: 24 hours.
Austin: 2 a.m.
Baltimore: 2 a.m.
Bloomington and Normal, Illinois: 1 a.m. on weeknights, 2 a.m. on weekends.
Bloomington, Indiana: 3 a.m.
Boston: 2 a.m. (lame)
Buffalo: 4 a.m., 24 hours on specific holidays. (surprising)
Champaign, Illinois: 2 a.m.
Charlotte: 2 a.m.
Chicago: Some bars may choose to close at 2 a.m. or earlier. They may alternately get an extension which allows them to close at 4 a.m. or earlier. On Saturdays, closing times are shifted an hour back to 3 and 5 a.m.
Cincinnati: 2:15 a.m. for last call; 2:30 a.m. for closing time.
Cleveland: 2:30 a.m.
Columbus: 2:30 a.m.
Denver: 2 a.m.
Florence, South Carolina: 2 a.m. for hard liquor, 3 a.m. for beer. This includes Sundays where any bar that is defined as a private club may operate 7 days a week, otherwise last call is midnight Saturday night, until the establishment reopens for business on Monday.
Fort Wayne, Indiana: 3 a.m.
Houston: alcohol service stops at 2:00 a.m.
Indianapolis: 3 a.m.
Kansas City, Missouri: 1:30 a.m. for most bars, 3:00 a.m. for specially licensed bars in certain geographic areas. 6:00 a.m. for one bar only, the Mutual Musicians Foundation. (Whoever owns that bar is sitting on a goldmine).
Las Vegas, Nevada: Bars may stay open 24 hours a day, 7 days a week.
Los Angeles: 2 a.m. (more like 1:30am, weak)
Lexington, Kentucky: 2:30 a.m.
Louisville: 4 a.m.
Miami: 5 a.m.; Bars may stay open 24 hours, 7 days a week in the Downtown Entertainment District.
Minneapolis / Saint Paul: 2 a.m.
Mobile: No last call for bars operating under a private club license
New Orleans: Bars may stay open 24 hours, 7 days a week.
New York City: 4 a.m., nightclubs are permitted to stay open after 4 a.m. but cannot serve alcohol.
Pensacola, Florida: 3 a.m. (within city limits, 2 a.m. for county)
Peoria, Illinois: Bars in the downtown district may stay open until 4 a.m. Bars in other areas may stay open until 1 a.m. Sunday through Wednesday and 2 a.m. Thursday through Saturday. Bars may stay open 2 hours later than normal closing hours on New Year's Eve, providing additional patrons are not allowed after normal closing hours.[14]
Phoenix / Scottsdale: 2 a.m.
Philadelphia: 2 a.m.
Pittsburgh: 2 a.m.
Providence: 2 a.m. on weekends, 1 a.m. on weeknights.
Rochester, New York: 2 a.m.
Salt Lake City: 1 a.m.
San Diego: 2 a.m. (more like 1:30am, weak)
San Francisco: 2 a.m. (more like 1:30am, weak, although SF places are known to break rules, thank God.)
Savannah, Georgia: 3 a.m.
Seattle, Washington: 2 a.m.
Shreveport, Louisiana: 6 a.m. for Downtown, 2 a.m. everywhere else.
St. Louis: 2 a.m. on Weeknights, 3 a.m. on weekends.
St. Petersburg: 3 a.m.
Tampa: 3 a.m. (not bad)
Washington, D.C.: 3 a.m. on Friday night, Saturday night, and the night before a federal or DC holiday; 4 a.m. on the night of New Year's Eve; 2 a.m. other nights.[15]
http://en.wikipedia.org/wiki/Last_call_(bar_term)