You are talking about a period from 1907 to 1922:
“The Law: Federal legislation that changed the status of married immigrant women so that not all of them would automatically obtain the citizenship of their husbands
Date: September 22, 1922
Also known as: Married Womans Act
Significance: In 1907 a federal immigration law was passed that specifically stated that upon marriage a woman would take the nationality of her husband. The Cable Act changed this, except for women who were American citizens and married men who were ineligible for American citizenship under federal law because of their race.”
http://immigration-online.org/397-cable-act-of-1922.html
Please show the legislation and case law prior to 1907.
Here you go.
Prior to it being codified, it was just an accepted practice.