As you may know, I usually start every episode with the birth date and place of the main character. In this case, I have found conflicting evidence for Henry. Two sources say that he was born on the 12th of March, 1862 in Germany, yet one source specifically states that he was born in Finland on the 15th of May 1875 under the name Uno Henrik Toivonen. According to this source, he survived the sinking of the SS Franklin in 1893 and joined the US Navy after coming to the States. Although I cannot verify this information via another source, enlisting in the US Navy and deploying in support of the Spanish-American War does match up with the other sources. Henry was a Seaman when his actions earned him the Medal of Honor. The citation reads:

On board the U.S.S. Marblehead during the operation of cutting the cable leading from Cienfuegos, Cuba, 11 May 1898. Facing the heavy fire of the enemy, Hendrickson displayed extraordinary bravery and coolness throughout this action.

Henry did receive his Medal of Honor on the 7th of July 1899, and once again, this is where some unverified information comes into play. Supposedly, he was married in Brooklyn, New York, moved back to Finland, had two children, and then moved back to the US but I can’t find any information to confirm this. Henry Hendrickson died on the 28th of February, 1912 and he is buried in the Mount Hope Cemetery in Boston, Massachusetts: Elm Grove Section, Lot 4105.