Custody Act of 1839
Before this act, during a divorce the custody of children tended to go directly to the father, as children were in a way considered property of the man of the house. This act, however, allowed a mother to petition the court for custody of her children up to about age seven.
(https://en-academic.com/dic.nsf/enwiki/11595789#:~:text=If%20previously%....)