The new cathedral was originally planned to be built on a "Bishop's Block" on Main Street. As the city's business district began to encroach on that location, Bishop Loras terminated the plan. In 1857, construction began on land just north of the old cathedral building. On July 5, 1857, a large crowd watched as the cornerstone was laid. The cathedral was based on Magdalen College in Oxford, England. The architect was John Mullany, a local architect who designed New Melleray Abbey, and St. Mary's Church. He originally designed the cathedral in the Romanesque Revival style, however, the Panic of 1857 forced a change in plans and it was constructed in the Gothic Revival style instead. Despite his failing health, construction had advanced far enough that Bishop Loras was able to offer the first mass in the new cathedral on Christmas Day, 1857. He died two months later.