"Mississippi State is a program on the rise," he said, "because Dan Mullen is a great head coach and his assistants do a great job.
"I look forward to contributing to their future success."
Mullen has reached into Louisiana twice in recent years to sign signal-callers Dak Prescott and Williams.
"Dak is a great guy," Williams said. "He showed me a very good time on my visit. Mississippi State is a very family-oriented university. They make you feel like you're at home, and I'm ready to spend four or five years there."
Williams was patient during the recruiting process, waiting it out until mid-January when he made the initial verbal to Southern Miss.
"I lost a lot of offers because schools were pressing me to commit and I wasn't ready," he said. "But Southern Miss was there for me from the beginning until the end, and that stuck out to me.
"It was definitely a blessing to have those guys recruiting me. It didn't work out, but I thank God for the opportunity...and now, here I am as a Bulldog."
Rummel successfully rumbled through its 2012 schedule without a loss. The (14-0) Raiders defeated Barbe to capture the 5A state title.
"I want to compliment my teammates because, as you know, football is a team game and no one person can do it alone," Williams articulated.
"Those guys on the team did a great job of complementing my game. We guys stuck together to get that perfect season and (championship) ring."
Williams said the Raiders made a commitment to excellence during the off-season.
"The thing that made state go great was the blood, sweat and tears that we all put into it," he explained. "And compliments to our coaching staff for sticking with us, because they could have accepted other job offers and left to go elsewhere."
As a senior, Williams threw for approximately 2,800 yards. He was selected as Rummel's most valuable player following the Raiders' masterful 35-14 win over Barbe in the state finals.
In that game, Williams connected on 11-of-13 pass attempts for 193 yards and two touchdowns.
Williams also lit up the Brother Martin Crusaders in a pivotal district tilt, rushing for 181 yards and completing 8-of-10 for 167 yards and two TDs.