Despite his qualifications, he faces an uphill confirmation battle with Republicans vowing to not even consider the nomination during this election year.
"I have fulfilled my constitutional duty. Now it's time for the Senate to do theirs," Obama said.
"Either way, our view is this: give the people a voice in filling this vacancy," said U.S. Sen. Mitch McConnell, Republican majority leader.
MERRICK GARLAND SPEAKS ABOUT CHICAGO ROOTS
On Wednesday, Garland became emotional when he spoke of his roots in the Chicago area, and his mother who still lives in Lincolnwood.
He is Harvard-educated and has spent much of his professional life in Washington, but he remains a Chicagoan at heart. And his formative years here pointed toward great success.
On Wednesday, the sign at the entrance to Niles West High School congratulated Garland on his nomination. And he spoke of his roots in the community in a video the White House released on YouTube.
"This is not anything I could have ever imagined growing up in Lincolnwood, Illinois. My mother will be watching on TV, she's still alive. She'll be crying," Garland said.
The video - designed to promote his nomination - introduces viewers to his family: wife Lynn and two daughters. It shows the personal side of a man described as "a brilliant legal mind."
As a teenager he volunteered in campaigns for Congressman Abner Mikva, later becoming his press secretary. They remain close to this day.
"Nobody can argue with his credentials. He is just always been fair, he's been admired by people," Mikva said.
Mikva says President Obama was fulfilling his constitutional obligation by nominating Garland to the Supreme Court. And he says the Senate has an obligation to hold hearings. Experts, however, say it's unlikely.
"Much of this is theater and much of this Merrick Garland had to agree to put himself through, knowing that the likelihood of his nomination was minimal," said Harold Krent, Chicago-Kent College of Law.
"It's gonna make it difficult for Republicans to oppose somebody who is so well-respected and really is so centrist in his outlook on the law," said Dr. Artemus Ward, a political science professor at Northern Illinois University.
Back when he roamed the halls at Niles West, Garland was multi-talented: a valedictorian, science whiz, lead in the school play, and captain of the TV quiz show team.
He served as president of the student council and was voted "most intelligent" by his peers, and was even the graduation speaker for his Class of 1970. It was a forecast of things to come, even if we don't know how it ends.
"People just knew him as a brilliant guy and a down-to-earth guy," said Howard Bulgatz, Niles West Class of '70.
"The whole Niles West family is proud. He really exhibits the characteristics that we try to instill in our kids here today," said Dr. Jason Ness, principal at Niles West.
The principal says Garland is a lock for another nomination this spring: Niles West Alumnus of the Year.
Some experts say Garland's best chance of being confirmed to the court might be if a Democrat wins the White House and the Senate calls hearings before the new president takes office.
OBAMA CHALLENGES GOP WITH HIGH COURT NOMINATION
Standing in the White House Rose Garden with Garland, Obama argued the integrity of the court was at stake and appealed to the Senate to "play it straight" in filling the seat left vacant by the death of Justice Antonin Scalia.
"It's supposed to be above politics," Obama said of the high court. "It has to be. And it should stay that way."
Republican leaders, however, held to their refusal to consider any nominee, saying the seat should be filled by the next president after this year's election. Senate Majority Leader Mitch McConnell spoke with Garland by phone but did not change his position that "the American people will have a voice." He said he would not be holding "a perfunctory meeting but he wished Judge Garland well," a spokesman said.
Others in the GOP ranks were less wedded to the no-hearing, no-vote, not-even-a-meeting stance - a sign that Republicans are aware the strategy could leave them branded as obstructionist.
Unlike McConnell, Senate Judiciary Committee Chairman Charles Grassley said he is open to meeting with Garland in the coming weeks, as did five other Republican senators - Rob Portman of Ohio, Jeff Flake of Arizona, Susan Collins of Maine, James Inhofe of Oklahoma and Kelly Ayotte of New Hampshire. The judge will begin visiting with Democratic senators on Thursday at the Capitol, before the Senate breaks for a two-week recess.
Scheduling courtesy meetings is a long way from securing a full hearing, much less winning the 60 votes needed for confirmation. Still, the White House seized the comments as evidence Garland's weighty resume and bipartisan credentials were putting pressure on Republicans.
Garland, 63, is the chief judge for the United States Court of Appeals for the District of Columbia Circuit, a court whose influence over federal policy and national security matters has made it a proving ground for potential justices.
A graduate of Harvard College and Harvard Law School, Garland has clerked for two appointees of Republican President Dwight D. Eisenhower - the liberal Justice William Brennan Jr. as well as Judge Henry J. Friendly, for whom Chief Justice John Roberts also clerked. As a federal prosecutor, he made his reputation overseeing the investigation and prosecutions in the Oklahoma City bombing case in 1995, as well as the case against Unabomber Ted Kaczynski.
When confirmed to the D.C. Circuit in 1997, Garland won backing from a majority in both parties, including seven current Republicans senators.
As a replacement for Scalia, Garland would undoubtedly shift the court away from its conservative tilt. He would be expected to align with the more liberal members on environmental regulation, labor disputes and campaign finance.
The D.C. Circuit isn't a hotbed for cases on social issues, leaving few solid indicators of Garland's views on abortion rights or the death penalty.
Garland's involvement in two high-profile gun rights cases has prompted concern from gun control opponents. In 2007, Garland wanted the full court to reconsider a panel decision that struck down Washington, D.C.'s ban on handgun ownership. But Garland never took a position on the merits of the case.
In 2000, he was part of a 2-1 majority that said the FBI could retain gun purchase records for six months to make sure the computerized instant background check system was working. The FBI's position was challenged by the National Rifle Association and other gun rights groups.
But he is not viewed as a down-the-line liberal. He's ruled against giving the District of Columbia a vote in Congress. Particularly on criminal defense and national security cases, he's earned a reputation as centrist with a law-and-order streak, siding more often with prosecutors.
When his name was floated for the Supreme Court in the past, it was liberal groups that expressed concerns, pointing to early decisions favoring the government in disputes over the legal rights of detainees at the Guantanamo Bay prison.
Progressives and civil rights activists also had pushed the president to name an African-American woman or to otherwise expand the court's diversity. Obama passed over appeals court Judge Sri Srinivasan, who would have been the first Asian-American justice, and Judge Paul Watford, who would have been the second African-American.
Garland - a white, male jurist with an Ivy League pedigree and a career largely in the upper echelon of Washington's legal elite - breaks no barriers. He would be the oldest Supreme Court nominee since Lewis Powell, who was 64 when he was confirmed in 1971.
In emotional remarks in the Rose Garden, he choked back tears, calling the nomination "the greatest honor of my life." He described his grandparents' flight from anti-Semitism in Eastern Europe and his modest upbringing. He said he viewed a judge's job as a mandate to set aside personal preferences and "follow the law, not make it."
Obama quoted past praise for Garland from Roberts and Sen. Orrin Hatch. In 2010, Hatch said he could be confirmed to the highest court "virtually unanimously."
Garland has experience with a prolonged confirmation process. He waited 2 years to win confirmation to the appeals court. Then, as now, one of the men blocking his path was Grassley, who argued he had no quarrel with Garland's credentials but objected to a Democratic president trying to fill an appeals court he felt had too many seats.
ILLINOIS POLITICIANS REACT TO NOMINATION
U.S. Sen. Mark Kirk of Illinois says he will assess President Barack Obama's nominee to the Supreme Court "on his record and qualifications." Kirk on Wednesday reiterated a stance he first took last month when he broke with some fellow Republicans who said Obama's successor should choose Scalia's replacement.
Kirk said it's the Senate's "constitutionally defined role to provide advice and consent" and that's "as important as the president's role in proposing a nominee." He reaffirmed his commitment to governing without political rancor when he returned to the Senate following his stroke.
Democratic Senator Dick Durbin released this statement Wednesday:
"I applaud President Obama's decision to nominate Chief Judge Merrick Garland. Judge Garland is an outstanding attorney and jurist with an admirable list of accomplishments. Born in Chicago and raised in Lincolnwood, Illinois, he received undergraduate and law degrees from Harvard and clerked for Judge Henry J. Friendly on the Second Circuit Court of Appeals and for Justice William Brennan on the Supreme Court. He served with distinction as a federal prosecutor and in several supervisory roles in the U.S. Department of Justice, and he also worked in private practice before he was confirmed in 1997 in a bipartisan Senate vote to serve on the United States Court of Appeals for the District of Columbia Circuit. He became Chief Judge of the D.C. Circuit in 2013. The President has fulfilled his constitutional responsibility and now the U.S. Senate must do the same. No Senate has ever denied a hearing to a Presidential nominee to fill a Supreme Court vacancy. In the name of fairness and our Constitution, the Senate Republican majority must do its job and give Judge Garland a public hearing and a timely vote."
Congressman Mike Quigley (IL-05) released this statement Wednesday:
"Congratulations to Chief Judge Merrick Garland, a fellow native Chicagoan, on his nomination by President Obama to the U.S. Supreme Court. Simply put, his exceptional federal judicial experience makes him highly qualified to serve on the Supreme Court. In considering Chief Judge Garland, President Obama has held him up to the highest of standards, and I believe he exemplifies the principles laid out by the president as being key to upholding our democracy today. Chief Judge Garland has dedicated his life to public service and has taken on some of the nation's most significant anti-terrorism cases, having run the Oklahoma City bombing investigation and the Unabomber investigation. Today's announcement is part of President Obama's constitutional duties. And now I urge the Senate to hold up their end of the constitution and move quickly to give Chief Judge Garland a fair confirmation hearing with an up-or-down vote. It is what the American people deserve from their government."
The Associated Press contributed to this report.