Ms Canfield's sister, Connie Anderson, joined Mr Obama in Ohio
A letter written to President Obama by a cancer sufferer struggling to pay insurance premiums played a prominent role in his fight for health reform.
Natoma Canfield's letter was referred to by the president in speeches he made across America.
Ms Canfield told how in 2009 she paid out more than $10,000 in premiums and fees while her insurance provider paid out less than $1,000 on her behalf.
She was then told that her premium for 2010 was to rise by 40%.
Ms Canfield, 50, beat cancer 16 years ago but has recently been diagnosed with leukaemia.
The self-employed cleaner told Mr Obama she could no longer afford her health insurance and feared losing her home as a result of having to pay for her own care.
"I need your health reform bill to help me," she wrote in her letter,
now posted on the White House website.
"I simply can no longer afford to pay for my healthcare costs."
She added: "Please stay focused in your reform attempts as I and many others are in desperate need of your help."
As he pressed his case for reform, President Obama travelled to Ms Canfield's home state of Ohio and highlighted her story as an example of why the system needed changing.
"I'm here because of Natoma," he said.
"I'm here because of countless others who have been forced to face the most terrifying challenges in their lives with the added burden of medical bills they can't pay. I don't think that's right. Neither do you."
Ohio's Democratic Congressman John Boccieri said Ms Canfield's case made him rethink his position on healthcare reform and vote in favour of the bill.
He compared her story to that of his mother, who survived cancer when he was a child.
"Luckily, my mom had good healthcare insurance," he said.
"She survived. But how many people do not have healthcare insurance, and how would my life have changed if she did not make it? Where would I be?"