Republican Donald Trump and Democrat Hillary Clinton rolled up a series of wins on Super Tuesday, as the two presidential front-runners looked to take command of their party nominating battles on the 2016 campaign's biggest night of voting.
Clinton won seven states particularly across southern US states with great support from African-American voters.
However, Trump's victories were far and wide. He also won seven states from different parts of the US including Alabama and Georgia in the south, Massachusetts and Virginia in the northeast.
Clinton, the former secretary of state, hoped to win enough states to take a big step towards wrapping up her nomination fight with rival Bernie Sanders, a democratic socialist US senator from Vermont.
Sanders won his home state of Vermont, one of five states he was hoping to win on Tuesday. He thanked cheering supporters in his hometown of Burlington, Vermont, and took a shot at the Republican front-runner.
"We are not going to let the Donald Trumps of the world divide us," Sanders said, adding that he expected to pile up "hundreds" of convention delegates in voting on Tuesday.
Super Tuesday is the biggest single day of state-by-state contests to select party nominees for the Nov. 8 election to succeed Democratic President Barack Obama. Voting stretches from eastern states to Texas and Minnesota, with the first polls closing at 7 pm EST (midnight GMT).
Trump has worried many in the Republican establishment with proposals such as building a wall along the US southern border with Mexico, deporting 11 million illegal immigrants and slapping a temporary ban on Muslims entering the country.
But while his campaign has confounded many Republican leaders, the New York real estate developer cites his high poll numbers as proof he is not dividing the party but expanding its ranks. He preached unity as he looked beyond the day's voting to campaign in Ohio, which votes on March 15.