The 1930 U.S. Census indicated that Danielson worked as a house carpenter; he lived next door to the civil engineer, Floyd E. Stanbery in Pasadena, CA.

According to the 1930 U.S. Census, Danielson immigrated to the U.S. in 1911. His wife came to America in 1905. Danielson lived at 1567 East Topeka Street, Pasadena, CA, in 1930 with his wife. They owned the dwelling at that time valued at $7,500.

In 1930, Danielson was married to Anna S. Danielson, (born c. 1890 in Sweden).