How did Florida become part of the United States? Britain lost Florida to the United States during the American Revolution.
The United States bought Florida as part of the Louisiana Purchase.
Spain and the United States agreed to the Adams-Onís Treaty.
Italy sold Florida to the United States in exchange for a portion of California.

Florida became part of the United states

Explanation:

The reason they became part of the US is because Britain lost Florida to the United States during the American Revolution, since Britain failed to claim the land, United States bought Florida.

b.   jim crow laws were enacted in northern states.

uncle sam would be tossing and turning in his grave : *)