When Conrad Theodore Rostamo was born on 1 October 1891, in Minneapolis, Hennepin, Minnesota, United States, his father, Karl A. Rostamo, was 28 and his mother, Louise Loge, was 33. He married Leona H. Jackson on 14 October 1915, in Minneapolis, Hennepin, Minnesota, United States. They were the parents of at least 3 sons and 2 daughters. He died on 25 May 1965, in Minneapolis, Hennepin, Minnesota, United States, at the age of 73, and was buried in Mound Cemetery, Brooklyn Center, Hennepin, Minnesota, United States.