Charles and his wife Anna were found on the June, 1880 census in DC. He showed his occupation as a mathematical instrument maker. It says his dad was from Prussia and his mom from what looks like New Jersey. Anna and her family were all from Canada so perhaps they met in Minnesota where Charles was born. I am further wondering if he is an older brother to William Wurdeman as William had a son Charles and they both worked in the DC area in the same field...coincidence?