To be sure, the Institute for Supply Management's services sector index climbed to 60.3 in July, up from 56 in June. It was the highest reading in a decade.
This bolstered the case for a September rate hike, some say.
"This will be interpreted as very good news for the Fed and will be seen as further confirmation of progress towards meeting its growth targets," Cheng Chen, an economist at TD Securities in New York, told Reuters. "At this point, we continue to expect the Fed to raise rates at the September meeting."
In the Dow, gains in shares of UnitedHealth and those of Wal-Mart, last up 2.5 percent and 1.9 percent respectively, outweighed a plunge in shares of Walt Disney, last 9.3 percent weaker.
Walt Disney shares slid on disappointing sales. On the flip side, shares of Priceline jumped more than 6 percent as the company posted earnings that exceeded expectations.
Four out of five S&P 500 members have reported results this season, with about three-quarters beating profit estimates and half topping sales projections, according to Bloomberg.
While earnings are important, investors are focused on US policy makers.
"The single most important factor affecting stock markets is what the Fed is doing," John Manley, who helps oversee about US$233 billion as chief equity strategist for Wells Fargo Funds Management in New York, told Bloomberg.
Meanwhile, oil slid to the lowest level in four months amid fresh concern about a global glut.
In Europe, the Stoxx 600 Index finished the session with a 1.3 percent gain from the previous close. The UK's FTSE 100 Index climbed 1 percent, Germany's DAX Index rose 1.6 percent, while France's CAC 40 Index rallied 1.7 percent.