Democrat Barack Obama travels to the eastern state of Pennsylvania Friday, beginning a two-month campaign for the White House as the first African-American to lead a major party ticket.

Sen. Barack Obama, (r), and Democratic VP candidate, Sen. Joe Biden at the Democratic National Convention in Denver, 27 Aug 2008

Senator Obama and his running mate, fellow Senator Joe Biden, will be meeting voters and making speeches on a bus tour of key battleground states.

Thursday night, Obama appeared before nearly 80,000 cheering supporters to accept his party's historic presidential nomination.  He promised change and drew sharp contrasts with his Republican rival, John McCain.

In a speech filled with policy specifics, Obama said McCain would simply continue what he described as the failed policies of  President George Bush.

Obama vowed to end the Iraq war responsibly and finish the fight against al-Qaida and the Taliban.  He vowed to cut taxes for working families, stop giving tax breaks for corporations that move jobs overseas, and end U.S. dependence on foreign oil.

McCain's campaign called the speech "misleading" and "so fundamentally at odds with the meager record" of Obama, a first-term U.S. senator.