Mitt Romney says he and Paul Ryan gave all they had to their campaign — but that "the nation chose another leader."

His campaign of nearly 17 months came to an end with a concession speech in Boston, where Romney told supporters he wished he'd been able to "lead the country in a different direction."

Romney watched the returns from a Boston hotel, as one battleground state after another went to the Democrats.

In the aftermath of the loss, Republican campaign officials conceded that they'd had serious concerns about Romney's path to victory even before Superstorm Sandy struck last week. And their internal polls showed President Barack Obama's standing improving in the days after the storm.

In the end, Romney officials said they underestimated the level of turnout from Obama's supporters. And they said they didn't anticipate a surge in African-American turnout.