Lou Henry Hoover (née Henry; March 29, 1874 – January 7, 1944) was an American philanthropist, geologist, and the first lady of the United States from 1929 to 1933 as the wife of President Herbert Hoover. She was active in community organizations and volunteer groups throughout her life, including the Girl Scouts of the USA, which she led from 1922 to 1925 and from 1935 to 1937. Throughout her life, Hoover supported women's rights and women's independence. She was a polyglot, fluent in Mandarin Chinese and well-versed in Latin, and was the primary translator from Latin to English of the complex 16th-century metallurgy text 'De re metallica.'