The author
Laura Ingalls Wilder's husband's name was Almanzo (b. 1857). In one of her books, she explained the name thus: "My folks have got a notion there always has to be an Almanzo in the family, because 'way back in the time of the Crusades there was a Wilder went to them, and an Arab or somebody saved his life.
El Manzoor, the name was. They changed it after a while in England..."
This is very probably the same "Al-Mansur" you mentioned.