The NFL free agency frenzy is upon us. This period of the offseason marks the new league year and shakes up rosters across the league. Over the years, the San Francisco 49ers have made some game-changing acquisitions through free agency, signing players who've become key contributors to the team's success.
With just a day away from the free agency negotiating window that begins on March 12th, let's look back at some of the greatest free agency signings in 49ers history.
Deion Sanders

Signing in 1994 after leaving the Atlanta Falcons, Sanders played one season in San Francisco. He won the NFL Defensive Player of the Year award in 1994, recording six interceptions, three of which were returned for touchdowns. His contributions helped the 49ers win Super Bowl XXIX.
Ken Norton Jr.

Norton Jr. joined the 49ers in 1994 from the Dallas Cowboys and played linebacker for seven seasons (1994-2000). He recorded multiple 100-tackle seasons and was a key part of the team's Super Bowl XXIX victory. Norton is the one of the only players in NFL history to win three consecutive Super Bowls, having won two with Dallas before joining San Francisco (tied with Eagles OL Darian Kinnard).
Tim McDonald

Joining the 49ers in 1993 from the Arizona Cardinals, Tim McDonald played safety for seven seasons (1993-1999). He was selected to three Pro Bowls during his career in San Francisco and recorded 20 interceptions, 545 tackles, and 7.0 sacks. He was a defensive leader on the team's Super Bowl XXIX-winning roster.
Jeff Garcia

Signed from the CFL's Calgary Stampeders in 1999, Garcia became the 49ers starting quarterback in 2000. He was selected to three Pro Bowls (2000-2002) and led the team to multiple playoff appearances. In 2001, he threw for 32 touchdowns and over 3,500 yards.
Justin Smith

The 49ers signed Smith in 2008 from the Cincinnati Bengals. He played defensive line for seven seasons (2008-2014), earning five consecutive Pro Bowl selections (2009-2013) and a First-Team All-Pro nod in 2011. Smith recorded 43.5 sacks with the 49ers and was a key part of the team's defensive front during their NFC Championship appearances from 2011 to 2013.