First stint with the GiantsBrown was drafted by the 
New York Giants in the fourth round (129th overall) of the 
2009 NFL Draft. He suffered a ruptured 
Achilles tendon during training camp on August 14, which forced him to miss his rookie season. He was placed on 
injured reserve on September 1, 2009. Brown was waived by the Giants on September 4, 2010.
[1]
Denver BroncosOn September 5, 2010, Brown was claimed off waivers by the 
Denver Broncos, waived on September 15, and then signed to the Broncos' practice squad on September 17, 2010. On September 21, 2010 Brown was signed to the active roster, and 
Lance Ball was waived.
[2] Brown himself was waived on October 16, 2010. In four regular season games with the Broncos, Brown played in three but only amassed statistics in one (two rushes for a total of minus one yard in a 31-17 road loss to the 
Baltimore Ravens on October 10, 2010).
[3]
Indianapolis ColtsBrown was claimed off waivers by the 
Indianapolis Colts on October 18, 2010. Brown was moved to the Colts active roster on November 6, 2010, then waived on November 9, 2010. Brown did not amass any statistics in his only game with the Colts, a 26-24 road loss to the 
Philadelphia Eagles on November 7, 2010.
[3]
Carolina PanthersBrown was claimed off waivers by the 
Carolina Panthers on November 9, 2010, and then waived on November 16, 2010.
[1] Brown did not play in his only game with the Panthers, a 31-16 road loss to the 
Tampa Bay Buccaneers on November 14, 2010.
[3]
Washington RedskinsOn November 24, 2010, Brown was signed by the 
Washington Redskins and added to their active roster.
[4] He was released on July 28, 2011.
[5]
Second stint with the GiantsOn August 3, 2011, Brown re-signed with the 
New York Giants.
[6] He was waived on September 3, but re-signed the next day to the practice squad. On February 5, 2012, Brown and the Giants won Super Bowl 46 against the New England Patriots. After the game Brown became known for his celebratory song, "I got a ring", he and his teammates sang on the plane ride home and at the parade the following week.
In March of 2012, Brown was hit with a four-game suspension by the NFL for violating the league's substance abuse policy. 
[7] He later claimed it was a result of 
Adderall use 
[8] and eventually won an appeal, having his suspension lifted. 
[9]
On September 16, after starter 
Ahmad Bradshaw was knocked out of the game with a neck injury, Brown rushed for 71 yards on 13 carries, converting a two-point conversion and scoring the game-winning touchdown against the 
Tampa Bay Buccaneers.
[10]
On September 20 of 2012, Brown stepped in as the starter for the Giants against the Carolina Panthers on Thursday Night Football. Brown rushed for 113 yards on 20 carries, scoring two rushing touchdowns. He also had 3 receptions for 17 yards.
On November 25, he suffered a broken fibula in the fourth quarter on a 
Sunday Night Football game against the 
Green Bay Packers at 
MetLife Stadium, effectively ending his season. He ended the season, where he participated in 10 games, with 73 carries for 385 yards, with a 5.3 yard per carry average, after only 2 carries in the previous 3 seasons. He was eventually placed on injured reserve.
[11]