This is the symbol for the Walther League, a youth society for the Lutheran Church Missouri Synod (LCMS).
The International Walther League was formed in 1893 and named after Rev. C.R.W. Walther.  The goal of the league was to assist in keeping young people within the Church.
Over the years the league established Lutheran hospices and supported the Evangelical Lutheran Sanitarium in Wheat Ridge, Colorado, which it owned and operated from 1927-1959. The league sent out over 400,000 Bibles and prayer books to U.S. servicemen during WWI and provided aid to the European Relief effort after the war. During the Great Depression the league ran local food banks and soup kitchens and helped fund the new Lutheran Hour radio program. By 1936 the Walther League had 85,000 members in 2,180 societies. An estimated 25,000 Walther Leaguers served in the military during WWII and the league turned their focus to aiding its military members. After WWII the league attracted a younger age group, of high school age. However, the high schoolers could not provide the financial support the working-age young adult members had provided and the league suffered financial and other problems. In 1977 the LCMS dropped its affiliation with the league and in 1989 the Walther League’s board of directors met for the last time. 
 The Walther League was named after Rev. Carl Ferdinand Wilhelm Walther (1811-1887), a German-American Lutheran minister. Rev. Walther was the first president of the Lutheran Church Missouri Synod from 1847-1850 and was reportedly its most influential theologian. Walther was born in Langenchursdorf, Kingdom of Saxony, educated at the University of Leipzig, emigrated to America in 1838, and accepted a Doctor of Theology degree from Capital University, Columbus, Ohio, in 1877. He is described as a man who gave up his homeland for the freedom to speak freely, to believe freely, and to live freely, by emigrating from Germany to the United States. Walther died in St. Louis, Missouri in 1887.
 “A Short History of the Walther League,” Walther League Redux, https://waltherleague.com/ , viewed 24 Apr 2023.