In relation to architecture, a cornerstone is traditionally the first stone laid for a structure, with all other stones laid in reference. A cornerstone marks the geographical location by orienting a building in a specific direction.

Cornerstones have been around for millennia, in some shape or form. In ancient Egyptian and Mesopotamian cultures, the equivalent of a “ground-breaking” ceremony was the “foundation ritual” which allowed the gods to protect a building. “Foundation deposits,” or hollowed out stones filled with small vessels, animal deposits, and other symbolic items, were standard in the construction of temples, palaces, tombs, and forts. Depending on the type of structure, the deposits were placed at the corners of buildings, or at points of importance in a structure, such as the entrance. This ensured that remains of the building’s original content were preserved with the structure throughout its life, until demolition.

Over the years, cornerstones have served a variety of purposes. As a means to preserve time, buildings have been marked with a numerical representation to remind people when the building was erected. This has given correlation to architecture and the design of the time. Additionally, cornerstones have become a strong symbol of a new era. They have indicated prosperity and opportunity—showing a sense of pride for what is possible at the time of construction. Cornerstones have also been turned into pieces of memorabilia, marking present buildings or denoting previously standing buildings. One example is the downtown Minneapolis Macy’s building, formerly Dayton’s Department Store. At the exterior base of the building is a plaque telling the story of the site’s previous tenant, Westminster Presbyterian, which was destroyed by fire in 1895. George Draper Dayton, the owner at the time, believed that the story, and recognition, of the church was important to display on the new building, even though the church had relocated to its current location at 12th Street and Marquette Avenue South.

As the commemorative qualities of cornerstones have become recognized, the locations of craftsmanship have expanded to stones near or above the front door of a building. Architects have used these spaces to declare ownership of the building’s design. There are many instances around Minneapolis and Saint Paul where the architect has left their name in the stone of the building.

Today, cornerstones are more commonly placed ornamentally as interior walls, the floor, or the façade of a building, depending on whether the intention of the stone is inscription or preservation. Often laid with a ceremonial trowel by a person of prominence, a local celebrity, or politician, it can be said that the primary purpose of a cornerstone is the publicity that comes with the ceremony. Preservation, in some cases, has become as important as the marking of a building as is seen with time capsules, hollowed-out stones filled with popular objects, or something significant to the occupants of the building at the time of completion.