[2] The defensive Union Fort was founded to help secure the area for the early farmers living nearby, and it also provided security for shipments of granite (or quartz monzonite) from the mouth of Little Cottonwood Canyon for the construction of the Salt Lake Temple.

1853, in consequence of Indian depredations and trouble, it was thought to be expedient to build a fortification and live inside the walls.

The wall which had port holes was built of rock, clay and adobe twelve feet high around the sides.

The week of November 16, 1857, Twenty [men] from Union (joined about 1500 in the mountains) to, "check the advance of our enemies who were threatening to exterminate us from the earth."

February 1858 a great portion of the inhabitants of Union were plagued with a violent cough and cold, or influenza.

The most visible remnants of this era are the old preserved Jehu Cox house (moved from its original location and now used as a shop), about a block north of North Union Avenue in an area that is now a large parking lot, and a historic marker at the site of the fort.

The Utah Transit Authority and Wasatch Front Regional Council have proposed bus rapid transit lines connecting Fort Union to the TRAX light rail system to the west as well as north-to-south along the full length of 1300 East, but there are no concrete plans and ordinary bus lines are the only public transportation available.

The area bounded by State Route 71, Fort Union Boulevard, North Union Avenue, and the western slopes of the plateau on the north side of Little Cottonwood Creek has been filled with almost nothing but big-box store developments (containing some smaller-scale retail) and office towers, with associated parking facilities; previously, development had occurred mostly along the main roads through the area leaving big gaps of open fields that were quickly filled-in during the 1990s.

Hillcrest High School is on the west side of State Route 71 near South Union Avenue.

Mountview elementary school, which had not been in use for years, was torn down in 2011 to make room for a new park at the northeast corner of the Fort Union commercial district.