Final answer:
The first U.S. MAC store opened in 1991 in New York City.
Step-by-step explanation:
The first U.S. MAC store opened in 1991 in New York City, specifically in the Greenwich Village neighborhood of Manhattan. MAC Cosmetics was founded by Frank Toskan and Frank Angelo in 1984 in Toronto, Canada. The brand quickly gained popularity for its diverse range of makeup products and collaborations with celebrities and fashion designers.