After six weeks of bus tours, train rides, bowling, cow-milking, chocolate tastings, beer sipping, speeches on race, debate questions about flag pins, gaffes about "bitter" small town Pennsylvanians and increasingly sharp exchanges with his opponent, Sen. Barack Obama ended his long march through the Keystone state last night with rallies in McKeesport and Pittsburgh that attracted thousands of people eager to hear his message of change.

Mr. Obama was 45 minutes late for the rally at the Petersen Events Center at the University of Pittsburgh in Oakland, but the crowd of 10,000 people didn't seem to mind, greeting him and his wife Michelle with a deafening roar when they walked on the stage at 10:15.

After a series of introductions by Teresa Heinz Kerry, Mrs. Obama and Sen. Bob Casey, Mr. Obama began to speak, recalling his six weeks in the state -- bowling with Mr. Casey ( "I didn't do so well") and pulling a train whistle during his whistle stop tour over the weekend.

While occasional shouts of "I love you Obama!" rang through the arena, Mr. Obama launched into a speech that lasted about 50 minutes. In it, he refrained from some of the harsher criticisms he's lobbed at Mrs. Clinton in recent days, saying she has "many good ideas and in fact we share a lot of ideas and policies, but I believe I am more committed to bringing about the change that is necessary....

"Whatever differences Mrs. Clinton and I have, we'll be unified in November to prevent a third term" of President Bush's policies.

"At the beginning of this campaign we said we would try to change the tone in our politics and we have done that,," he said. "We haven't been perfect ... but the core of this campaign has been to say... we can disagree without being disagreeable."

Before appearing in Oakland, Mr. Obama spoke at the Penn State Greater Allegheny campus in McKeesport.

Mrs. Clinton "is a hard-working, fine public servant." Mr. Obama told that crowd. "But Sen. Clinton does not recognize the need to fundamentally change the way Washington works."

In his abbreviated appearance -- after arriving almost two hours late -- Mr. Obama took final round counter-punches at Mrs. Clinton over her campaign advertising and stirred up the Mon Valley crowd with economic promises.

The Clinton campaign's latest "3 a.m." ad on experience shows pictures of Osama Bin Laden, Pearl Harbor and the Cuban missile crisis, in questioning which candidate "has what it takes" to be president.

Mr. Obama fought back, alluding to his opposition to the Iraq war, which Mrs. Clinton initially supported.

"Let me ask you a question," he said at a small, town hall style meeting. "There are three candidates left. Who do you want answering that 3 a.m. phone call? The person who got Iraq wrong, or the person who got Iraq right? The person who paid attention to the intelligence, or the person who didn't?" he said.

Though late, Mr. Obama still earned ear-shattering screams in McKeesport from a crowd of 2,200, mixed between black and white, young and old.

"When we come together there is no destiny we cannot fulfill, no problem we cannot solve," he said to the diverse crowd, on why he was running for president. "So I was making a bet that the American people were ready for a real change. Not itsy-bitsy change, but real change."

Due to his lateness -- much of the crowd had been waiting for three hours by his arrival -- the Illinois senator did a 22-minute speech, followed by another 22 minutes of questions and answers. First he sent out his wife, Michelle Obama to apologize.

"On behalf of the Obama family, sorry. It was Barack's fault," she said.

Before last night's event in Oakland, thousands of people had lined the sloping sidewalks of Cardiac Hill.

While most everyone in the line was wearing or brandishing some form of Obama endorsement, some said that they were not eligible to vote -- or planning to vote for someone else -- but could not pass up the opportunity to hear the senator for themselves.

Bakari Thompson, 16, a high school junior from the North Side, traveled by bus with his three 15-year-old sisters because "we're hoping for change."

They're not old enough to vote, but they vowed that they would "try to convince others to vote for him," he said.

Pitt freshman Brian Conrad, 19, of Coatesville, Chester County, is a registered Republican and unable to vote for either Democrat today. But he and four dorm-mates wanted "the once-in-a-lifetime chance to see a future president."