In 1870 the Bettina Literary Society of German Wallace College was organized for the purpose of intellectual development. In 1896 with the aid of Dr. Carl Riemenschneider, President of the college, the society was reorganized into the Philomathean Society. In 1918 the organization took the name of Phi Lambda Sigma and obtained its state charter in 1924.
Phi Lambda Sigma became Alpha Pi Chapter of Beta Sigma Omicron, a national sorority, on March 23, 1929. Mrs. Robert Fitzpatrick Orth of St. Louis, acting president of Grand Council, presided over the installation of the new chapter.
Beta Sigma Omicron was elected to membership in National Panhellenic Congress on October 12, 1933.