Schumacher was born in Hamburg; his name is found on a ship's manifest from Halifax, Nova Scotia, in 1751, at which time his profession is given as "candidate of theology".
His education was poor, and he had no ministerial qualifications; even so, Lutheran congregations in Pennsylvania needed a pastor, and he was able to make a living at the profession.
Schumacher kept records of various pastoral acts, decorating them with images of flowers and angels; from 1754 until 1773 he kept a similar book of his own, noting each child he baptized or confirmed.
[1] Schumacher was a controversial figure during his life, being accused of drunkenness on numerous occasions, and leaving his first wife soon after their wedding.
He eventually ran afoul of his superior, Henry Muhlenberg, who ultimately dismissed him from his post as a pastor; he did, however, have supporters elsewhere in the Lutheran community, and was able to find another position.