Morrow was a member of the New Mexico Territorial House of Representatives in 1897 and 1898 and the city attorney of Raton in 1900 and 1901. He was president of the board of education 1903-1923. In addition, he was a delegate to the Democratic National Convention in 1908 and a regent of New Mexico Highlands University in Las Vegas, New Mexico (the former state normal institution) from 1921-1922. He was elected as a Democrat to the Sixty-eighth, Sixty-ninth, and Seventieth Congresses (March 4, 1923-March 3, 1929) and was an unsuccessful candidate for reelection in 1928 to the Seventy-first Congress. After leaving Congress, he engaged in banking, had extensive ranch and livestock holdings, and was a large owner of real estate in Raton. He died in Santa Fe, New Mexico in 1935 and was buried at the Fairmont Cemetery, Raton, New Mexico. His gravestone reads "One more Game Lost".