CNN  — 

Members of a federal labor union visiting a Georgia Republican’s congressional office Monday said they discovered a 19th-century book on display that they considered “racially offensive.”

The American Federation of Government Employees is asking Rep. Drew Ferguson for a formal, public apology after its members said they found the book “General Robert Edward Lee; Soldier, Citizen and Christian Patriot,” which presents Confederate ideology.

Union members said that the book – published in 1897 – was displayed open to a page reading, “The blacks are immeasurably better off here than in Africa, morally, socially, and physically. The painful discipline they are undergoing is necessary for their instruction as a race, and, I hope, will prepare and lead them to better things.”

In a statement provided to CNN Wednesday by his spokesman, Ferguson, the Republican chief deputy whip, said he was unaware the book was even in his office and that it has since been removed.

“The office was decorated by staff and the book in question was underneath a box of military challenge coins. I did not even know it was there,” Ferguson said. “When my staff learned about it, they removed it and apologized to the individual who was upset by it.”

The congressman later told CNN in an interview that he is “certainly as offended by the remarks in that book as anybody would be, and that’s why it’s no longer in the office.”

Asked how a book like that ended up in his office without his knowledge, Ferguson told CNN that his office houses many history books.

“Sometimes those books are left in. Sometimes they go back somewhere else. I don’t know,” Ferguson said. “It’s a historical book of a very, very tragic time and bad time in our nation’s history. Reading things that you don’t agree with to help form an opinion is part of the learning process.”

While a group of six union members were waiting for a meeting with Ferguson, they were invited to sit in the reception area of his office. Octavius Miller, one of the union representatives, who works with the Transportation Security Administration, said he noticed the book in a glass case near the reception area’s chairs. When he noticed the pages the book was open to, he was shocked.

confederate book us government union members congress office

“The fact that this passage feels that me and my ancestors of color are immeasurably better off in the United States of America being slaves than we were in Africa, that is so disrespectful,” Miller said. “My first reaction was to flip this little case upside down, and I had to think about why I was there, what I do for a living, but the disrespect and the inattention to everything that people who are colored like myself and the pigmentation of my skin had to deal with … it enraged me.”

Union members had gone to Ferguson’s office to discuss TSA workers’ rights, part of a legislative conference that the union arranges every year and members from around the country attend. The American Federation of Government Employees is a federal labor union that represents more than 700,000 federal employees from different agencies.

Miller decided to take photos of the pages because he “could not believe” what he was seeing, he said, and later shared them with CNN. Ferguson, who represents Georgia’s 3rd Congressional District and was a dentist before beginning his political career in 2016, is Miller’s congressman.

The union local President Shekina Givens, who was with the group, asked a staffer in Ferguson’s office if they knew what the book on display said. The staffer said he wasn’t aware of the book or the passage, according to Miller, but told the group they also had a section of George Washington’s hair on display in the office.

The union members were not able to meet with Ferguson – there was some scheduling confusion between the union and his office, Miller said.

The union contacted Ferguson’s office later Monday asking for the book to be removed and for an apology from the congressman, according to a union spokesperson.

Miller told CNN he received a call from Ferguson’s chief of staff, Bobby Saparow, Tuesday morning apologizing and telling him the book had been removed.

“He said he wasn’t aware the book was there. He apologized maybe 15 times on the phone,” Miller said. “It seemed as if they just said what was necessary to try to mitigate the situation.”

The union called for a formal apology from Ferguson in a statement to CNN.

“It is utterly despicable that Congressman Ferguson would dare display such a racist item so prominently in his office,” National President J. David Cox Sr. said in the statement. “I am mortified for Mr. Miller and any other constituent who have had the misfortune of seeing this racist book while just trying to visit their member of Congress here in the nation’s capital.”

Asked Wednesday if he plans to issue a more formal apology, Ferguson told CNN, “I think that we’ve already done that. We spoke to the gentleman. I think we’re good.”

A CNN producer did not see the book during a brief visit to Ferguson’s office to ask the congressman’s staff about the incident.

CNN’s Lauren Fox and Veronica Stracqualursi contributed to this report.