Hans was born in Korsør, Denmark on the 9th of April, 1877 and he immigrated to the US on the 29th of August, 1899 through San Francisco. He enlisted in the US Navy and served in the Spanish-America War. Hans deployed to China in support of the Boxer Rebellion and it was his actions as a Seaman that would earn him the Medal of Honor. The citation reads:

Served with the relief expedition of the Allied forces in China on 13, 20, 21 and 22 June 1900. In the presence of the enemy during this period, Hansen distinguished himself by meritorious conduct.

Hans received his Medal of Honor the following year and he moved to Toms River, New Jersey to run a pigeon farm. It appears that he was married twice, first to Anglesea who died in 1921, and second to Mary with whom they had a son, William, together. Hans Anton Hansen died on the 23rd of August, 1949, on his porch in Toms River, New Jersey, where he is buried with his wife and son in the Riverside Cemetery: Lot 163C.