Doug Keillor, executive director of Madison Teachers Inc., said that the union was contacted by school officials Monday saying interim Superintendent Jane Belmore decided to rescind the firing of Marlon Anderson.
Anderson said in a Facebook post Monday afternoon, "I'm back!!" He said he learned of his rehiring while at his new job Monday.
"Thank you to the 1,000 plus students for allowing your voices to be heard and to all the people from across the globe for reaching out to my family," Anderson said in his post.
Keillor said Anderson, 48, will be on paid leave as he works with the district on a transition plan back to the school.
"We are very pleased," Keillor told The Associated Press.
In a statement to staff, Belmore said she is "prepared to take appropriate steps in the current situation, and I will begin to work with our administrative team to ensure that we mitigate any harm that was caused and begin the healing process and give the board time to review our practice."
"Our commitment to anti-racism and to use the input from community, especially our students is unwavering," Belmore said.
Earlier, Madison School Board President Gloria Reyes said she asked the superintendent to rescind Anderson's termination and to review the use of racial slurs in school.
"As we experienced a series of racial slurs last school year, we had to take a stand - that we would unequivocally protect students from harm. That we would never excuse the deep pain of this hateful, violent language, regardless of intent," Reyes said.
But she added: "It is important that we do not harm those that we are trying to protect."
It was unclear if Reyes was speaking for herself or the entire school board. She did not immediately return messages seeking comment Monday.
Earlier, Anderson said he was not angry about his firing because he has received "a busload of love" from supporters.
Anderson told WMTV-TV on Sunday that he hasn't had time to be upset because of support he has received. He said people have stopped him on the street to hug him. Students from Madison West High School also staged a walkout Friday in support.
Anderson said he was responding to a call Oct. 9 about a disruptive student when the student, who is black, called him obscenities, including the N-word. Anderson told the student not to call him that, repeating the slur.
The school district has said it has a zero-tolerance policy on employees using racial slurs.
Reyes had said last week she wanted the district to resolve a grievance over Anderson's firing as quickly as possible.
The school fired Anderson on Wednesday, but the Boys & Girls Club of Dane County hired him and he started Monday.
"I didn't have an opportunity to be mad, scared, worried or anything. I just got hit with a busload of love," Anderson said.
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