She accused President Bush of conducting "an administration that says, 'This isn't a big deal, this war isn't going to cost much, just go about your lives."' As a result, "A lot of our families feel like they're going through this alone because the rest of the nation has been sort of implicitly told, 'Don't worry."'
Obama received a standing ovation at Cedar Crest College when she said the Illinois senator will "responsibly end the war in Iraq."
More than 1 million veterans live in Pennsylvania - a key battleground state in the November election - and the Obama campaign has been trying to make inroads with families of soldiers who have faced multiple deployments to Iraq and Afghanistan.
This month, about 4,000 Pennsylvania National Guard members headed to Mississippi to begin training for deployment to Iraq early next year, the state guard's largest mobilization in decades.
As part of his pitch to military families, Obama has pledged to strengthen veterans' health care, combat homelessness among veterans, and crack down on employers that discriminate against part-time members of the military.
His opponent, Republican nominee John McCain, who spent five-and-a-half years as a Vietnam POW after being shot down in 1967, has also promised to improve services for military families, including helping veterans find civilian employment, increasing military pay and expanding access to health care.
At Cedar Crest, women whose husbands and sons have served in Iraq told Michelle Obama about the challenges and stressed they've faced back home.
Jill Slivka, 31, said she struggled to keep the household afloat while her husband was deployed to Iraq in 2006 and 2007. She said her son, who was entering kindergarten at the time, couldn't understand why his father had left and lashed out at school and at home, eventually requiring therapy.
Kathleen Miller, 58, said she had difficulty coping when her two sons went to Iraq.
"It is very, very difficult to send a child to war and wait for their uncertain return," she said. "Sometimes I would feel like I was an alien, inasmuch as I would go about doing my daily activities, but nobody would really know ... what was going on inside me as a mother."
Obama was joined on stage by Jill Biden, wife of Obama running mate Joe Biden, whose eldest son, Delaware attorney general Beau Biden, is a captain in a National Guard unit that is to be deployed to Iraq.
The two wives were to appear later Wednesday at a campaign rally in Philadelphia.