A system of government where nobles governed and protected the people in return for services suck as fighting in the army and farming the land

A system of government were Nobles governed is called feudalism.

populist movement, in u.s. history, politically oriented coalition of agrarian reformers in the middle west and south that advocated a wide range of economic and political legislation in the late 19th century. thus in 1892 their leaders organized the populist, or people's, party, and the farmers' alliances melted away.

may i ask which amendments?