When World War I broke out, she returned to the United States to pursue a career in opera. After a six-week tour through her home state, in which she gave twenty-six concerts, she went back to Paris and was offered the lead in Manon at the Opéra Comique. She performed the role in rented costumes and makeup borrowed from Mary Garden. When the United States entered the war in 1917, Peterson visited and performed at various army camps. In 1918 she signed a six-year contract with the Metropolitan Opera of New York, where she sang with Enrico Caruso and John McCormack. Among her favorite roles were Micaela in Carmen and Mimi in La Bohème. Her golden voice and personality soon won her international fame as the "Golden Girl" of opera. Even then, she continued giving benefit concerts for the Methodist Church during the off-season. She made several records under the Vocalion label and was one of the first American artists to sing on radio.
In 1921 Emil Myers arranged to have May Peterson appear in concert at the First Methodist Church in Amarillo. The local civic committee selected attorney Ernest O. Thompson to be her escort. A romance ensued, and the two were married on June 9, 1924, in Bronxville, New York. Afterward they returned to Amarillo to a glittering reception held in the ballroom of the Amarillo Hotel, which Thompson had built and owned. May Thompson retired from the opera after her marriage, but she continued doing concert tours for several years. In 1925 she sang in the first musical festival to be staged at the Amarillo Municipal Auditorium, and she regularly assisted with local musical programs. In 1932, after Thompson was appointed to the Railroad Commission, the couple moved to Austin, where Mrs. Thompson became a leading figure in musical circles. The Thompsons had no children. On October 1, 1952, May Thompson suffered a cerebral hemorrhage at their summerhouse in Estes Park, Colorado, and lapsed into a coma. She was flown back to Austin, where she died in Seton Infirmary on October 8 without regaining consciousness. She was buried in the State Cemetery in Austin.
30° 15.908, -097° 43.624
Texas State Cemetery