Pho began entering the U.S. mainstream during the 1990s. Vietnamese refugees had already introduced the soup to American communities after the Vietnam War, but improving U.S.–Vietnam relations helped pho move beyond Vietnamese neighborhoods and into wider public awareness.
The first major wave of restaurants developed in places with large Vietnamese populations, especially California and Texas. Little Saigon in Orange County became an important center: the first of hundreds of pho restaurants there opened in 1980. During the 1990s, restaurants spread rapidly along the Gulf and West Coasts, then expanded to the East Coast and other parts of the country.
This timing is easy to confuse with pho’s earlier arrival. Refugee communities were serving it in the United States in the 1970s and 1980s, but “entering the mainstream” describes broader acceptance, restaurant growth, and visibility. By the 2000s, pho restaurants were generating an estimated $500 million in annual U.S. revenue, and the dish had begun appearing on college and corporate campuses.