The Dow Jones Industrial Average closed at 13,075.66, up a hefty 187.73 points (1.46 percent).
The S&P 500-stock added 25.95 points (1.91 percent) at 1,385.97 and the tech-rich Nasdaq leaped 64.84 (2.24 percent) to 2,958.09.
A slightly better-than-expected number on US growth in the second quarter still underlined the snail's pace of the world's largest economy, fueling speculation about additional support from the Federal Reserve.
The government's announcement that gross domestic product grew 1.5 percent in the April-June period, after 2.0 percent in the prior quarter, sent shares skyward.
"That is lousy, but expectations had dropped so low that the spin is coming out as 'not too bad,'" said Dick Green at Briefing.com.
It also helped push the Dow over the psychological barrier of 13,000 for the first time since May 7, when it closed at 13,008.53.
The leaders of Germany and France, Europe's two biggest economies, vowed to preserve the embattled eurozone amid a sovereign debt crisis.
In a joint statement, German Chancellor Angela Merkel and French President Francois Hollande pledged to do "everything to protect the eurozone."
Their show of force helped to maintain momentum in the markets a day after European Central Bank chief Mario Draghi's pledge to do "whatever it takes" to save the euro fueled global stock rallies.
Merck shares jumped 4.1 percent, leading the 30-stock Dow higher. The drugmaker posted an 11 percent fall in earnings, beating market estimates.
Fellow Dow blue-chip Chevron rose 0.9 percent after the oil giant reported better-than-expected quarterly profit.
Investors unfriended Facebook. Shares plunged 11.7 percent after the world's social media leader reported disappointing first earnings as a public company amid concerns about how it intends to grow profits from mobile products.
Amazon leaped 7.9 percent after the online retailer said profit in the second quarter shrank 96 percent, generally in line with expectations.
Delta Air Lines inched up 0.1 percent after announcing it was closing regional carrier Comair on September 29, resulting in the loss of 1,700 jobs.
Bond prices tumbled. The 10-year Treasury yield rose to 1.56 percent from 1.43 percent Thursday, while the 30-year climbed to 2.64 percent from 2.49 percent. Bond prices and yields move in opposite directions.