Earlier, the S&P and Dow struggled to hold opening gains before climbing as oil prices extended gains.
U.S. crude oil futures settled up $1.86, or 5.2 percent, at $37.75 a barrel after weekly crude inventories from the EIA showed a draw of 4.9 million barrels.
The U.S. dollar index touched its lowest since Oct. 2015 before recovering slightly, with the euro near $1.14 and the yen at 109.7 yen against the greenback. Earlier, after the Fed minutes' release, the yen hit 109.4, a fresh high against the dollar since Oct. 2014.
We'll "see how Japanese equities react tonight. If (the dollar/yen) keeps sliding then there's going to be some problem," Klein said.
Overnight, the Nikkei 225 fell 0.11 percent for its first seven-day losing streak since November 2012.
The Federal Open Market Committee minutes from the March 15 to 16 meeting were released at 2 p.m. ET. At that meeting, the central bank kept rates unchanged and lowered its projections for the number of hikes this year to two from four.
Treasury yields recovered from Tuesday's decline to hold slightly higher. The 2-year yield was near 0.74 percent and the 10-year yield at 1.75 percent.
"I'm a little surprised we didn't give back a little bit of it from the Fed minutes, which I though emphasized a little more the risks from abroad more than we had heard from the Fed previously," said Sharon Stark, managing director and fixed income strategist at D.A. Davidson.
St. Louis Fed President James Bullard said the Fed could raise rates at any meeting, or even between meetings, according to a Bloomberg Radio interview cited by Reuters. However, he noted the pieces of data since the Fed's March meeting have been "mixed," making it potentially difficult for the Fed to raise rates this month.
Ahead of the Fed minutes release, Cleveland Fed President Loretta Mester said she expects a gradual series of interest rate hikes this year given recent U.S. economic strength.
"It will be appropriate to continue to gradually reduce the degree of accommodation this year," she told the Cleveland Association for Business Economics.
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European stocks ended more than half a percent higher.
In Asia, the major averages were narrowly mixed. The Shanghai composite also ended mildly lower while the Hang Seng gained slightly.
The Caixin/Markit services PMI for March rose to 52.2 from February's 51.2, but the employment sub-component fell to 48.9 from 51.3, pointing to the first contraction in staffing levels since August 2013.