While its size and grandeur often make people question if Notre Dame Church is a cathedral, it is not. A cathedral is not determined by the size of a building, but as the church of a bishop who is the pastor of a diocese. At the beginning of the 20th century, there was such a large influx of French-Canadians into New England that plans were developed to build the Grand Trunk Railroad to connect parts of New England with Canada. Southbridge was intended to be a major commercial and cultural center along the rail line. The expectation was that this large influx of French-Canadian Catholics would eventually establish Southbridge as a central Catholic base and the future home of a new diocese to be separated from Springfield. However, history intervened when the principal supporter of the Southern New England Railway, a subsidiary of the Grand Trunk Railway, Charles Melville Hays, sailed on the Titanic in April of 1912. The construction began on March 25, 1911. The church is constructed of white marble with a red Spanish tiled roof, and measures 190 feet in length. The nave is 78 feet across and the transept is 123 feet across.
Though the original plan called for the church to be built of red brick, Msgr. Triganne made the change to white marble bricks. A quarry in Lee, Massachusetts had been commissioned by the government to cut tombstones for the casualties from the Spanish-American War. Miscalculating the tragedy, a large number of stones remained quarried but unused. Msgr. Triganne contacted Lee Marble Works and had the former tombstones cut into bricks so that there were enough not only to build the church but ten years later to face the west and north sides of the adjoining rectory as well.