Americanophile
/əˌmɛrɪˈkɑːnəʊfʌɪl/noun
A person who loves or admires the United States or its culture.
adjective
Characterized by love of or admiration for the United States or its culture.
Origin
Late 19th century; earliest use found in The New York Times. From American + -o- + -phile, perhaps after Anglophile, Francophile, etc.