How did the Land Act of 1800 make land ownership more affordable for settlers in the west?

Jefferson believed that small farmers should control the West. The Land Law of 1800 reduced the minimum individual purchase of land in the West to 320 acres. That minimum was slashed to 160 acres in 1804, and again in 1820 to 80 acres.

necessary and proper clause. the congress shall have power to all laws which shall be necessary and proper for carrying into execution the foregoing powers, and all other powers vested by this constitution in the government of the united states, or in any department or officer thereof.