“But my grandfather had larger dreams for his son. Through hard work and perseverance my father got a scholarship to study in a magical place: America, which stood as a beacon of freedom and opportunity to so many who had come before. While studying here, my father met my mother. She was born in a town on the other side of the world, in Kansas. Her father worked on oil rigs and farms through most of the Depression.”

The hall grew hushed as Obama continued: “My parents shared not only an improbable love, they shared an abiding faith in the possibilities of this nation. They would give me an African name, Barack, or ’blessed,’ believing that in a tolerant American your name is no barrier to success.”

But the American dream held some challenges for Obama, who wrote about his father’s return to Kenya early in the marriage and his own struggle with identity in a 1995 memoir, “Dreams From My Father: A Story of Race and Inheritance.”

Raised by his maternal grandparents in Hawaii, Obama attended Columbia University and Harvard Law School, where he was the first black editor of the prestigious Harvard Law Review. He moved to Chicago, where he entered politics, winning a state Senate seat representing the Hyde Park neighborhood on the South Side — a racially mixed district dominated by the University of Chicago, where he lectures on law.

He and his wife Michelle, also an attorney, live in Hyde Park with their two daughters.

Obama’s moving evocation of his American journey was the rhetorical highlight of the four-day Democratic gathering and his debut on the national stage.

The 42-year-old state lawmaker is poised for a nearly uncontested election to the U.S. Senate in November.

After winning the Democratic primary with a surprising 53 percent of the vote in a seven-candidate field, Obama expected a tough general election battle against Republican nominee Jack Ryan, a telegenic millionaire who had quit his job to teach in an all-black private academy in one of the Windy City’s toughest neighborhoods.

However, Ryan’s campaign imploded when unsealed divorce court records revealed allegations from his wife that he had asked her to engage in public sex at swingers’ clubs in Paris and New York.

Ryan denied the charges but withdrew from the race after intense pressure from party leaders, who have failed to recruit anyone to run in November. That leaves Obama facing token opposition from independent candidates.

If elected, Obama would become the first popularly elected black U.S. senator since Edward Brooke of Massachusetts left the chamber in 1979.

Though he’s headed to Capitol Hill, Obama’s convention performance left even some of the most cynical pundits predicting a future at the other end of Pennsylvania Avenue.

Throughout his speech, Obama used his own life story to appeal to the notion of America as “E Pluribus Unum” — “Out of Many, One” — to draw connections between countrymen of all colors, creeds, and classes.

“Alongside our famous individualism, there’s another ingredient in the American saga,” said Obama.

“A belief that we are connected as one people. If there’s a child on the South Side of Chicago who can’t read, that matters to me, even if it’s not my child. If there’s a senior citizen somewhere who can’t pay for her prescription and has to choose between medicine and the rent, that makes my life poorer, even if it’s not my grandmother.

“If there’s an Arab American family being rounded up without benefit of an attorney or due process, that threatens my civil liberties. It’s that fundamental belief — I am my brother’s keeper, I am my sister’s keeper — that makes this country work. It’s what allows us to pursue our individual dreams, yet still come together as an American family.”

Obama’s appeal cleaves across not only lines of color and class but party as well.

When he came to Boston six months ago seeking campaign funds for the primary race, he camped out in the office of prominent Republican operative Sandy Tennant, who had met the state senator during a business trip to Chicago.

“I absolutely believe Barack represents not only the best in government and politics but the best in America,” said Tennant. “Forget about whether you’re a Republican or a Democrat, this guy is great for our country.”