The chain of laws would be the two Militia Acts of 1792, then the Militia Act of 1795 which made 1792’s Presidental powers permanent, then the Militia Act of 1862 where they expanded every able bodied white male citizen to include black males, then the Militia Act of 1903 which made the organized militia officially into the National Guard and the unorganized militia of all other male citizens (and those who have stated formal intention to become a citizen this time) into the unorganized Reserve Militia, and then finally the National Defense Act of 1916 providing funding to the National Guard and creating the ability to draft the Guard for overseas service.
The chain of laws would be the two Militia Acts of 1792, then the Militia Act of 1795 which made 1792’s Presidental powers permanent, then the Militia Act of 1862 where they expanded every able bodied white male citizen to include black males, then the Militia Act of 1903 which made the organized militia officially into the National Guard and the unorganized militia of all other male citizens (and those who have stated formal intention to become a citizen this time) into the unorganized Reserve Militia, and then finally the National Defense Act of 1916 providing funding to the National Guard and creating the ability to draft the Guard for overseas service.