WINDSOR, ENGLAND - Members of the Kappa Kappa Gamma sorority had a surprise for the now-Duchess of Sussex on her wedding day.

As the Ascot Landau carriage paraded in the procession after Meghan Markle's and Prince Harry's marriage at St George's Chapel on May 19, a group of Kappa Kappa Gamma alumnae from all over the U.S. sang a wedding chant reserved for members on their wedding day.

Margaret Phipps from Texas said Markle's eyes lit up when she saw them.

"It was a really special moment," Phipps said. "We came all this way. It means so much for us to have that moment with her."

The traditional wedding Kappa Kappa Gamma chant is called "Oh Pat."

Markle was a member of the Kappa Kappa Gamma sorority when she attended Northwestern University. She graduated from NU in 2003.

Video by Miranda Tomlinson, special for 12 News.