Abstract William Truesdell designed the Seventh Street Improvement Arches, which stand near Minnesota at St Paul. McArthur brothers, together with Michael O’Brien, were the construction contractors. After examination of several available design options, Truesdell settled for oblique method due to the nature of the intersection of the street at Duluth tracks and the St. Paul. He used stones that were sourced from locally available quarries in the construction of the bridge. This paper reports on the various events that unfolded during the construction of Seventh Street Improvement Arches. It also discusses the methods, equipment, tools, and labor that were used in the construction process. Besides, it speculates on the ways that the construction would have been done if the bridge were to be made today. Introduction Seventh Street Improvement Arches refer to a slanted overpass that is situated near Minnesota in the United States of America. The double-arched bridge was built using the spiral method that is alternatively referred to as helicoidal viaduct-building methodology. Up to date, the Seventh Street Improvement Arches remain historically significant in civil engineering due to their intricate technical and architectural design that required much precision in terms of stonecutting. During the time of designing and construction (1883-1884), the bridge stood as unique based on the few of such bridges that were in existence in the US. Today, the bridge constitutes the only known example of bi-arch brickwork helicoidal overpass in Minnesota. Hence, the artistic creativity of Engineer William Truesdell was necessary. McArthur brothers, together with Michael O’Brien, took up the challenge of the actual creation of the art piece of work (Minnesota’s Historic Bridges Para 3). Their success in delivering the project derivable is evidenced by the up-to-date well-standing bridge at St Paul, Minnesota, although the overpass is not currently in use. This paper summarizes and discusses the 1883-1884 building process of the Seventh Street Improvement Arches. It also speculates and analyzes how the structure (whether a building, road, dam, canal, or bridge) would be made if it were built today. Summary of Events Seventh Street Improvement Arches as shown in fig. 1 below was among a number of constituents of a project that was proposed and scheduled for improving the ‘Seventh Street’ that was to connect various regions in 1883. Other tasks of the project included the construction of Iron Bridge that measured 300 ft in length at Northern Pacific Railway and the construction of masonry-arch for the septic tank at the Phalen Creek crossing. Seventh Street Improvement Arches comprised two main curves. The West curve has a span of 41ft. The East arch has a span of 30 ft. The arc barrel extends to 124ft. Figure 1: Seventh Street Improvement Arches. Source: (Minnesota’s Historic Bridges Para 1) At the dawn of 1883, the Minnesota administration announced that it had directed St. Paul to ensure the issuance of bonds for improving the ‘Seventh Street.’ The specific place of improvement of the avenue was where “it crossed the combined valley of Trout Brook and Phalen Creek that linked the downtown district with Dayton’s Bluff to the east” (Minnesota’s Historic Bridge