It was a second day of gains following big falls earlier in the week linked to worries about the Chinese economy. Chinese markets were closed due to a public holiday.
The Dow Jones rose 23 points, or 0.1%, to close at 16,375, while the S&P 500 rose 0.1% to 1,951.
The Nasdaq fell slightly, closing down 16 points, or 0.4%, at 4,734
Non-farm payrolls figures for August are due out on Friday. They are expected to show a similar rise to the 215,000 jobs that were added in July.
US shares had made bigger gains earlier in the day after European Central Bank chief Mario Draghi hinted there might be more stimulus measures to come for the eurozone.
The chipmaker Intel was the biggest gainer, rising 1.7% the day after it unveiled its new range of processors at a technology show in Berlin.
Construction equipment maker Caterpillar, down 2.2%, was the biggest faller on the Dow Jones.
"I think the market is trying to calm down a little bit with the fear factor reducing somewhat and the data points to a growing US economy," said Peter Cardillo at Rockwell Global Capital in New York.
(Close): Wall Street shares closed slightly higher on Thursday ahead of Friday's jobs report.