By Jeff Mason

EL DORADO, Kansas (Reuters) - Democrat Barack Obama, who is famous as the most viable black presidential candidate in U.S. history, said on Tuesday rival Hillary Clinton's celebrity gave her an advantage in the crucial, multi-state nominating contests next week.

Obama campaigned in Kansas in the town where his maternal grandfather was born, reaching out to voters in a traditionally Republican state and seeking to build broad-based support after a resounding win over the former first lady in South Carolina.

But the Illinois senator told reporters it was Clinton's own fame as a former first lady and New York senator that gave her an edge in the more than 20 states that on Tuesday vote to determine the presidential nominee in November's election.

"There's no doubt that Senator Clinton has a big advantage going into the February 5th states," he said as he flew from Washington to Kansas.

"She's much better known and, you know, I am still being introduced to a lot of casual voters in the other states," he said.

Candidates Obama, Clinton and former Sen. John Edwards of North Carolina all campaigned heavily in the early voting states of Iowa and New Hampshire, but the unusually tight nominating schedule has forced them to scramble in the slew of states voting next Tuesday. Kansas is one of those states.

Obama campaign manager David Plouffe said the senator was well placed financially to compete in each of the contests and the campaign was running radio or television advertising in each of those states except Illinois, Obama's home, which he is expected to win handily.

In Kansas Obama sought to connect with voters through his family ties to the state, and he picked up the endorsement of popular Democratic Gov. Kathleen Sebelius, who delivered the nationally televised Democratic response to President George W. Bush's State of the Union address on Monday.