The Mackinac Bridge is a suspension bridge spanning the Straits of Mackinac to connect the non-contiguous Upper and Lower peninsulas of the U.S. state of Michigan. Envisioned since the 1880s, the bridge was completed in 1957 only after many decades of struggles to begin construction. Designed by engineer David B. Steinman, the bridge (familiarly known as "Big Mac" and "Mighty Mac") connects the city of St. Ignace on the north end with the village of Mackinaw City on the south. It is the third longest in total suspension in the world and the longest suspension bridge between anchorages in the Western hemisphere. The Mackinac Bridge carries Interstate 75 across the straits.