"I created the shirt because I'm proud of my heritage, I'm proud to be from the South," Mason Deering told KENS-TV.
The senior student barely made it passed first period at MacArthur High School before being sent to the principal's office.
A teacher viewed his shirt as controversial.
And North East Independent School District policy stated anything distracting or disruptive to learning is prohibited at the principal's discretion.
"It's not up to us to decide what's wrong with the shirt, per se, we just know from past experience that this is the type of shirt, the slogan that was on it, that can certainly cause controversy," NEISD spokeswoman, Aubrey Chancellor told KENS-TV.
While waiting for the principal, the assistant principle asked mason to change his shirt.
Mason claims the assistant principal told him the shirt was racist.
He refused to change and left the school.
"He chose to leave, which I think was the right decision because he wasn't doing anything wrong," said Robert Deering, who stands by his son, and says neither the shirt nor his son is racist.
"We have family, Stonewall Jackson in our family, that was in the Confederate army and we're proud of that. That's part of our heritage. And that's all he's doing right now and he believes in it and I'm fine with that," Robert Deering explained.
The principal never met with mason but told district administrators he wouldn't have made Mason change his shirt and that he can wear the shirt in the future as long as it's not a distraction.
(Reporter): "Do you plan on wearing the shirt again?"
(Mason): "I'm going to wear it on Monday."
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