A conservative law firm has filed lawsuits on behalf of individuals who say they were asked to leave the Smithsonian National Air and Space Museum or the National Archives Museum in January over pro-life messages on their attire.

The American Center for Law and Justice said in a lawsuit that students and chaperones from Our Lady of the Rosary School in Greenville, S.C., who traveled to Washington to participate in the National March for Life Jan. 20 decided afterward to visit the nearby National Air and Space Museum. Once inside the Smithsonian museum, the firm said, the group was "accosted several times" by staff who said they must either leave or remove their hats reading, "Rosary PRO-LIFE." The plaintiffs said they were discriminated against for the message on the hats, which they said they also wore to be able to keep their group together in the large crowd at the March.

The firm also said that other visitors to the museum the same day were permitted to wear various types of hats inside.

Another group of plaintiffs, some of whom were identified as Catholic, alleged in a similar lawsuit announced Feb. 8, that they chose to visit the National Archives Museum while in Washington for the March for Life and were asked to remove or cover up slogans such as "Life is a HUMAN RIGHT," or "Pro-Love is the New Pro-Life" while inside.

In a statement provided to OSV News, a spokesperson for the Smithsonian said, "We apologize that visitors to the National Air and Space Museum were asked to remove their hats on Friday, Jan. 20."

"A security officer mistakenly told young visitors that their pro-life hats were not permitted in the museum," the spokesperson said. "Asking visitors to remove hats and clothing is not in keeping with our policy or protocols. We provided immediate retraining to prevent a re-occurrence of this kind of error."

The spokesperson added that "the Smithsonian welcomes all visitors without regard to their beliefs. We do not deny access to our museums based on the messages on visitors’ clothing," adding that additional information on their policies for visitors is available on their website.

A spokesperson for the National Archives did not immediately respond to a request for comment from OSV News.

Reports of students being asked to leave the museum due to pro-life slogans on their hats sparked controversy, and prompted a response from congressional lawmakers.

In a Feb. 6 letter to Smithsonian Secretary Lonnie G. Bunch from members of Congress that was signed by both of the Palmetto State's Republican senators, Sens. Tim Scott and Lindsey Graham, lawmakers asked for more information about the alleged incident.

"As a federal entity and the recipient of more than $1 billion in federal funds every year, there should be no debate as to whether the First Amendment applies to the Smithsonian," the letter said. "We are deeply concerned about this unjust expulsion of young Americans from museums -- subsidized with taxpayer dollars -- for wearing apparel that your staff disagreed with.”

As of Feb. 9, hats like the ones worn by the students were available for purchase on the Our Lady of the Rosary School's website.