Around two dozen veterans joined the candidate for the announcement.
Several topics were brought up at the press conference, including veteran homelessness, the crisis at the VA, and the state of the military budget.
Cotton said: "Whether it is the failures at the VA or his failed foreign policy, President Obama has not done right by our veterans.
As a U.S. Army veteran, I will always be a voice for Arkansas's 250,000 veterans and their families.
I firmly believe the U.S. Senate needs more men and women who have served in the military, not less."
Cotton for Senate is a statewide coalition of over 400 Arkansas veterans.
Veterans for Cotton will perform traditional volunteer activities such as phone calls, yard sign distribution, and door-to-door, they will also be active on social media.
The Pryor Campaign released the following statement:
"At the end of the day, this campaign is about two very different records of serving Arkansans in Congress, and while Mark has introduced and passed into law measures to expand benefits for those who serve our country, Congressman Cotton has yet to offer a single bill aimed at helping veterans.
What Congressman Cotton has done, however, is vote for a proposal that cuts military pensions, something no other Republican or Democrat from Arkansas supported.
"Tom Cotton deserves our thanks for wearing the uniform and serving our country, but in Washington he simply hasn't been there for Arkansans."