The swearing-in of Sen. John Thune Tuesday marked a bit of history: The Murdo native became only the second South Dakotan to start a fourth U.S. Senate term.

Thune joins Karl Mundt as the only South Dakotans to get four Senate terms.

While that was historically significant for South Dakota, a more historic moment took place for the country. Kentucky Sen. Mitch McConnell became the longest serving Senate leader. McConnell was first elected to lead the Republican Senate caucus in 2006, and during his run he has served as both majority leader and, as he does now, minority leader.

NEWS: Republican who violated residency rule tapped to work in Secretary of State’s Office