James F. Wilson

While in the United States House of Representatives, he had prominently opposed the 1867 effort to impeach President Andrew Johnson. However, he voted for the subsequent 1868 impeachment of Johnson, and served as a manager (prosecutor) during Johnson's impeachment trial.
In the last half of the nineteenth century, two unrelated Iowans named James Wilson achieved high office, necessitating an early form of disambiguation. Representative and Senator James F. Wilson (of Jefferson County, Iowa) became known as "Jefferson Jim" Wilson, while Representative and Secretary of Agriculture James Wilson (of Tama County, Iowa) became known as "Tama Jim" Wilson. Provided by Wikipedia