Obama touches down in his 50th state: South Dakota

Air Force One touched down at Watertown Regional Airport in South Dakota at 4:28 p.m. local time Friday, marking the 50th state President Obama has visited while in office.

And with that, Obama joined another exclusive club: Presidents who have visited all 50 states. Only Richard Nixon, George H.W. Bush, and Bill Clinton have racking up that number. (George W. Bush hit only 49, never visiting Vermont.)

"I have now been to all 50 states as president, and I was saving the best for last," Obama told the graduating class of the Lake Area Technical Institute, a South Dakota community college. "To the other 49, I hope you take no offense."

Obama has made a concerted effort this year to complete the list, focusing on Republican-leaning states that he had little reason to visit, politically speaking.

In the months leading up to this trip to South Dakota -- where he will deliver the commencement address at a community college -- Obama made first visits to Idaho, Utah, and South Carolina.

Over the course of his presidency, Obama has focused on states he carried — or wanted to carry — in his 2008 and 2012 election bids.

The president's most-visited states are the ones that border Washington, D.C.: Virginia (72 Obama visits) and Maryland (64).

Mark Knoller of CBS News, who collects presidential statistics, runs down some other Obama-favored states:

• New York (49 visits) has been a favorite destination, mostly because of the United Nations and fundraisers from wealthy Democratic donors.

• Ohio (41 visits) is an electoral swing state that was critical to Obama's 2012 re-election.

• Florida (38 visits) is another important electoral state as well as a fundraising mecca for Democrats, Knoller writes.

So will Obama also visit the seven U.S. territories that he famously counted in addition to states while seeking delegates for the Democratic nomination in 2008?

"I don't have any additional travel to chart out for you at this time," deputy White House Press Secretary Eric Schultz told reporters aboard Air Force One.

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