Chicago opened the door of opportunity to a wider field. The pastor of Trinity found in that city a group of young men, enthusiasts in the Sunday School, and progressive in their aims. Dr. Vincent at once became a leader among them and by their aid was able to introduce a Uniform Lesson in the schools of the city. He established in 1865 a _Sunday School Quarterly_, which in the following years became the _Sunday School Teacher_, in its editorials and its lesson material setting a new standard for Sunday School instruction. His abilities were soon recognized by the authorities in his church, and he was called to New York to become first General Agent of the Sunday School Union, the organization directing Methodist Episcopal Sunday Schools throughout the world, and in 1868, secretary and editor. He organized and set in circulation the Berean Uniform Lessons for his denomination, an important link in the chain of events which in 1873 made the Sunday School lessons uniform throughout America and the world. It is the fashion now to depreciate the Uniform Lesson Plan as unpedagogic and unpsychologic; but its inauguration was the greatest forward step ever taken in the evolution of the Sunday School; for it instituted systematic study of the Bible, and especially of the Old Testament; it brought to the service of the teacher the ablest Bible scholars on both sides of the Atlantic; it enabled the teachers of a school, a town, or a city to unite in the preparation of their lessons. Chicago, New York, Brooklyn, Boston, and many other places soon held study-classes of Sunday School teachers, of all grades, of a thousand or more gathered on a week-day to listen to the lectures of great instructors. The Plainfield (N. J.) Railroad Class was not the only group of Sunday School workers who spent their hour on the train passing to and from business in studying together their Sunday School lesson. [Illustration: Old Business Block and Post-Office]