The original Saint Patrick's church was a wooden structure,[4] built in 1831 to support the Irish workmen who had moved to Lowell, largely to work on the Pawtucket and Merrimack Canals. Prior to its construction, they were attended by Rev. John Mahoney, a Catholic clergyman from a nearby town. By 1830 there were over 400 Roman Catholics in Lowell, and on July 3, 1831, St Patrick's Church was consecrated, led by Mahoney. Mahoney left in 1836 to work in Boston, and was succeeded by E.J. McCool.[5]
The current stone structure dates to 1853, although a fire in 1904 caused much of the church to be rebuilt by 1906.[6]
St. Patrick's is located on the eastern edge of the Lowell neighborhood known as The Acre, an area where Irish immigrants originally settled in squatters' camps to work in Lowell's mills. The church overlooks one the city's power canals, at the junction of Suffolk and Cross Streets. It is built in a cruciform plan out of coursed rubblestone with ashlar granite trim. A tower 160 feet (49 m) in height projects from the front facade, with stone buttresses flanking the main church entrance at its base. The entrance, as well as flanking entrances on either side, are set in Gothic lancet-arched openings. Above the main entrance is a three-part lancet-arched window, with the tall first stage of the tower completed by a smaller lancet window. The second tower stage houses a belfry with louvered lancet-arch openings, and it is topped by an octagonal steeple ornamented with lancet dormers.[3]