Yes, Kārlis Ulmanis was married. He married Broņislava Marija Plieksāne on April 4th, 1906, whom he had met while living in Switzerland from 1905-1907. They gave birth to two daughters, Daina and Astra. His wife died in 1933 from a kidney ailment, and Ulmanis never remarried.
The Legacy of Kārlis Ulmanis: How Well Do You Know Latvia's President?