Possible Clues:

• Part of NAFTA: Abbr
• Part of AAA
• Part of O.A.S.: Abbr.
• One of the major leagues: Abbr.
• Part of ASPCA
• AARP part: Abbr.
• Like the top medalists at the 2000 Olympics: Abbr.
• Res. of the U.S.
• Made in the U.S.
• Abbr. after N. or S.