Which Social Groups were initially left out of the U. S. Constitution?

Rights, But Not for Everyone

Women were second-class citizens, essentially the property of their husbands, unable even to vote until 1920, when the 19th Amendment was passed and ratified. Native Americans were entirely outside the constitutional system, defined as an alien people in their own land.

Explanation:

a social contract.

"a social contract is an agreement between citizens and their leader where the citizens give up certain freedoms in exchange for protection. the constitution of the united states is an example of a social contract."