Downtown's layout was first planned in 1833, 17 years before Salt Lake City was founded. Joseph Smith designed the Plat of Zion, a plan for cities of 20,000 people each that followed city blocks with self-sufficient family farms surrounding several temples in the center. Smith meant for this plan to be applied to the City of Zion in the Midwestern United States, but following persecution and Smith's assassination, the plans were carried westward by the Mormon pioneers. Downtown Salt Lake began to form in 1847 when Brigham Young chose the site of the Salt Lake Temple of the Church of Jesus Christ of Latter-day Saints, forming the core of the settlement. Temple Square became the center of the grid system, bounded by South Temple, West Temple, North Temple, and East Temple Streets. Streets are named according to their distance and direction from the southeast corner of Temple Square; for example 200 West is two blocks west of this meridian, while 400 South is four blocks south. East Temple was popularly known as Main Street, and was officially renamed sometime in the late 19th century. It remains as the commercial and economic center of the city today.
