WHO AM I? am the immigrant group that was faced with a famine and were discriminated against for being Roman Catholic

Irish Catholics.

Explanation:

The Roman Catholic population of the United States was mostly  English Catholics, But when several years of devastating potato FAMINE led millions of Irish Catholics to FLEE (immigrate)  to the United States in the mid 1840s,

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.