William Franklin Graham Jr. (Billy Graham) was an American evangelist and an ordained Southern Baptist minister who became well known internationally in the late 1940s. He was a prominent evangelical Christian figure, and was, according to a biographer, "among the most influential Christian leaders" of the 20th century. Graham held large indoor and outdoor rallies with sermons that were broadcast on radio and television; some were still being re-broadcast into the 21st century. In his six decades on television, Graham hosted annual "Crusades", evangelistic campaigns that ran from 1947 until his retirement in 2005. He also hosted the radio show Hour of Decision from 1950 to 1954. He repudiated racial segregation and insisted on racial integration for his revivals and crusades, starting in 1953; he also invited Martin Luther King Jr. to preach jointly at a revival in New York City in 1957. In addition to his religious aims, he helped shape the worldview of a huge number of people who came from different backgrounds, leading them to find a relationship between the Bible and contemporary secular viewpoints. According to his website, Graham preached to live audiences of 210 million people in more than 185 countries and territories through various meetings, including BMS World Mission and Global Mission.