Tgm stands for "The Great Migration," which refers to the movement of over six million African Americans from the rural Southern United States to urban areas in the North, Midwest, and West between 1916 and 1970. This mass migration was driven by factors such as economic opportunities, escaping racial segregation and violence, and seeking a better quality of life. The Great Migration had a profound impact on American society, culture, and politics, shaping the demographics and dynamics of cities across the country.