The Center for the Study of Politics and Governance at the Humphrey School of Public Affairs has issued this research on the total number of U.S. Senate candidates on the general election ballot throughout U.S. history. The U.S. has been holding U.S. Senate elections starting in 1914, so the report covers 100 years.

The report finds that New Jersey has had more U.S. Senate candidates on its general election ballots than any other state. This is not surprising, because New Jersey has had consistently easy petition requirements throughout its history. The 1890 law that requires 800 signatures for statewide independent candidates, and the nominees of unqualified parties, has never been amended.

The number of minor party and independent candidates for U.S. Senate is not entirely a function of how easy or difficult the ballot access laws are, though. Some states just have a political culture that has discouraged minor party and independent candidates. Mississippi has always had easy ballot access for both independent candidates and minor parties, yet Mississippi has had very few such candidates on the ballot throughout most of its history, although it has had many more in the past twenty years than it did previously. Mississippi has never required a petition for a party to gain a place on the ballot. The statewide independent petition in Mississippi was only 50 signatures between 1890 and 1955. In 1955 it was raised to 1,000 signatures. In 1966 the statewide petition was raised to 10,000 signatures, but the Voting Rights Section refused to pre-clear that change, so it went back to 1,000 signatures.