Bolton - Bolton filled the gap in their squad created by the sale of Gary Cahill by signing Tim Ream from the New York Red Bulls on Thursday.
The 24-year-old defender becomes the second United States international in the Premier League club's squad after midfielder Stuart Holden, and replaces Cahill following the England international's switch to Chelsea earlier in Europe's January transfer window.
Ream signed a three-and-a-half year contract but neither Bolton nor Major League Soccer's Red Bulls disclosed the transfer fee for a player that Bolton manager Owen Coyle said Arsenal wanted to sign before the start of the current English season.
"He is a US international - a player that year-on-year has progressed and got better, and he will continue to do that," Coyle said. "Tim is everything that we want in the players we are bringing to the club when we spend in the transfer market.
"He is young, has a tremendous attitude and a winning mentality."
A finalist for the MLS Rookie of the Year award in 2010, Ream was named on the MLS All-Star Team last year and has played seven times for the United States.
"This was a hard decision for me considering the fact that I enjoyed playing for the Red Bulls and was looking forward to the upcoming MLS season," Ream said. "However, after consulting with those closest to me, I decided that this was a once in a lifetime chance that I could not pass up."
Bolton are 17th in the 20-team Premier League, just a point above the relegation zone after 22 of 38 matches.