Original: During his appearance at the Norse-American Centennial in 1925, President Calvin Coolidge gave recognition to Leif Erikson as the Discoverer of America due to research by Norwegian-American scholars such as Knut Gjerset and Ludvig Hektoen.
Simplified: In 1925, American President Calvin Coolidge recognized Leif Erikson as the Discoverer of America. This was due to research by Norwegian-American scholars such as Knut Gjerset and Ludvig Hektoen.