After high school, Kaczur worked in construction for two years before attending the University of Toledo in the United States.

He started 51 games during his college career and became Toledo's first ever player to earn all-conference honors in four seasons.

After recovering from an injury that limited him to a reserve role behind Ryan O'Callaghan at right tackle for the first two months of the 2006 season, Kaczur returned to the starting lineup in November and helped the Patriots make a run to the AFC Championship Game against the Indianapolis Colts.

He was signed to a four-year, $16 million extension on August 24, 2009,[2] four months after the Patriots selected fellow offensive tackle Sebastian Vollmer in the second round of the 2009 NFL draft.

After suffering a back injury early in the Patriots' 2010 training camp, Kaczur missed all the preseason and was inactive for the first four games of the season before being placed on injured reserve on October 12, 2010.