Source: “Sevenich bei Muenstermaifeld in alter Zeit--Beitraege zur Genealogie der Maifelder Bauerngeschlechter” by Hans Bossier in “Die Maifelder ACKERMANN-Familie.” Bossier says that Johann married his sister-in-law (Anna) Maria Ackermann (after the death of her second husband Johann Weckbecker). However Anna Maria is reported to have died in 1735, before Johann Weckbecker died in 1737. Bossier also indicates that Johann married Katharine Brachtendorf in 1699.
Source of his birth date: Manfred Ruettgers. Source of his date of death: Records of St. Martin and St. Severus Catholic Church in Muenstermaifeld. Source of the information about his baptismal sponsors: FB Muenstermaifeld.
His baptismal sponsors were Joahnn Kirchem, a baker from Muenstermaifeld, and Margarete, the daughter of Anton [Ackermann?] of Sevenich.
He was a baptismal sponsor in 1680 for Johann, the son of his brother Nikolaus Sevenich and Anna Maria Ackermann of Sevenich; in 1691 for Elisabeth, the daughter of Peter Scheffer and Gertrud Adams of Keldung; and in 1693 for Johann, the son of Johann Philipp Kirchem and Maria Margarete Becker of Muenstermaifeld.
He may have been a baptismal sponsor in 1675 for Johann, the son of his sister Maria Lucie Sevenich and Adam Port of Gierschnach, and in 1683 for Elisabeth, the daughter of his first cousin once removed Leonard Ackermann and Maria Maur of Sevenich.

Source of her approximate birth year and the location of her wedding: Manfred Ruettgers. Source of her year of marriage and birthplace: “Sevenich bei Muenstermaifeld...” by Hans Bossier. Source of the other information: Records of St. Martin and St. Severus Catholic Church in Muenstermaifeld.
She was a baptismal sponsor in 1700 for Katharine, the daughter of her brother Martin Brachtendorf and Anna Port of Gierschnach.