Kappa Alpha Theta was based in part on two Fraternities with which Bettie Locke had contact; Beta Theta Pi, her father's fraternity, and Phi Gamma Delta (Fiji), her brother's fraternity. Bettie had many friends in Fiji, and when members asked her to wear their badge as a "mascot," Bettie declined. She said she could not wear it as she did not know the secrets and purposes represented by the letters. She followed her father's suggestion to begin her own fraternity for women, and so Kappa Alpha Theta was conceived. Bettie and her friend Alice Allen together wrote a constitution, planned ceremonies, designed a badge, and sought other women on campus worthy of membership. It took these women 3 years to found Kappa Alpha Theta. These four founding members initiated themselves on January 27, 1870, becoming the first Greek-letter fraternity known among women.

These four women proudly wore their black and gold badges to Asbury's chapel service on March 14. The Alpha Chapter at Asbury grew to 22 sisters. Soon Kappa Alpha Theta spread to other colleges with Bettie's establishment of the Beta Chapter at Indiana University in May of the same year. After the formation of Theta the men of Phi Gamma Delta presented Bettie with a silver cake basket engraved with their letters as a token of appreciation.

Through the years, Kappa Alpha Theta has grown to its current size of 125 college chapters, 282 alumnae groups, and more than 170,000 members. In 2005, Kappa Alpha Theta celebrated its 135th anniversary.

Some symbols of Kappa Alpha Theta are twin stars, a black and gold pansy, and the kite, which all represent the fraternity ideals of sisterhood.