On May 25, 1925, Struve married Mary Martha Lanning, who considered herself a musician but worked as a secretary at Yerkes. Lanning was slightly older than Struve and had been previously married. They had no children; thus the famous Struve astronomical dynasty came to an end. Other branches of the Struve family besides the line of Otto Wilhelm von Struve continued, but yielded no distinguished scientists. On October 26, 1927, Struve became a naturalized US citizen. At that time, he was fluent in spoken and written English, but had a slight German accent which remained with him for life. Even after marriage, Struve continued working days and nights, something that his non-scientist wife could not fully accept. Although they remained together, their relations were cold in later years. Struve's health deteriorated in the late 1950s. He was suffering from hepatitis, first contracted back in Russia and Turkey. In 1956, while using a telescope at Mount Wilson, Struve had a bad fall, breaking several ribs and cracking two vertebrae. He was hospitalized for about two months and had to wear a body cast for a month after recovery. He was permanently hospitalized around 1963 and died on April 6, 1963 in Berkeley. He was survived by his mother and wife. His mother died on October 1, 1964, at the age of ninety. Mary was discovered dead on August 5, 1966, but was estimated to have died in July 1966.