Copeland Avenue began in 1856, shortly after La Crosse was incorporated, as a narrow footpath that connected the city's northern and southern sections across a marshy stretch that often flooded and became impassable. North Side residents turned to engineer William R. Sill of the La Crosse Onalaska Plank Road Company, who supervised construction of a 20-foot-wide pine road raised 3 feet above the marsh, known as Plank Road, with tolls collected by custodian Gotthelf Herrold to pay for it. Within a decade, the city improved the route by raising it higher, widening it to 100 feet, and adding a macadamized limestone surface, after which it became known as the Causeway. As the lumber industry boomed over the next twenty years, traffic increased sharply and the North Side developed with small businesses, hotels, churches, and large mills along the northern section, giving the road the additional name Mill Street, while the southern portion where the Causeway joined Third Street was also called North Third Street. Mill and North Third remained interchangeable names until 1923, when the city officially renamed the entire stretch Copeland Avenue after Frederick A. Copeland, a prominent lumberman and former mayor of La Crosse, by which time the road had been resurfaced with brick. In 1984, two viaducts were built, one on Copeland and one on Rose Street, and traffic on each street was made one-way. Copeland Avenue's southbound traffic passes through a 5-acre strip of land that Mayor Copeland had donated to the city specifically for park use, and the surrounding commercial district has continued to develop and remains the heart of the North Side.