20th century research and practice of science led to advancement in the fields of communication, engineering, travel, medicine, and war. 20th century The 20th (twentieth) century was a century that began on January 1, 1901 and ended on December 31, 2000. It was the tenth and final century of the 2nd millennium. It is distinct from the century known as the 1900s which began on January 1, 1900 and ended on December 31, 1999. The 20th century was dominated by a chain of events that heralded significant changes in world history as to redefine the era: flu pandemic, World War I and
20th-century history of the Catholic Church in the United States greater frequency. 20th-century history of the Catholic Church in the United States The 20th-century history of the Catholic Church in the United States was characterized by a period of continuous growth for the Church in the United States, with Catholics progressively evolving from a small minority to a large minority. In 1900 the Catholic population was 10 million, under the control of 14 Archbishops, 77 bishops, and 12,000 priests . The community had built 10,000 churches, of which two-thirds had resident pastors. Catholic schools educated nearly 1,000,000 children and youth. Catholics were heavily concentrated in the industrial and mining centers