JOHN J. WELSH, the builder known in Camden as "The Man Who Built Broadway", was born in Philadelphia around 1857 to Anthony and Ellen Welsh. The 1880 census shows the family living in the 4000 block of Mason Street in Philadelphia. John J. Welsh was then working as a laborer. He married in the early 1880s.

John J. Welsh came to Camden with his wife Martha and son Edward in 1889. He is shown in the 1890-1891 city directory as living at 1064 Francis Street, a small street that lay between Front and South 2nd Streets and between Chestnut and Mount Vernon Streets. Another son, Frank Welsh, was born around 1892. There was a third son, John M. Welsh.

John J. Welsh soon established himself as a builder in Camden, and his firm erected many of the stores and commercial buildings on Broadway. He also erected the Union Methodist Episcopal Church at Fifth and Mount Vernon Streets in 1899. Other projects 

included the State Street Bridge, over the Cooper River east of 10th Street, the Grand Theater at 207 Broadway, and an addition to the old Courier Post Building at 3rd and Arch Streets. Early in his career as an independent contractor, John Welsh employed James H. Reeve as a foreman. Reeve would eventually strike out on his own and also played a major role in construction on Broadway and elsewhere in Camden.

A member of the Church of the Immaculate Conception at Broadway and Market streets, John J. Welsh, was also active in the political and civil life of Camden in the first three decades of the 20th century. For twenty years he was the treasurer of the Camden County Democrat Party committee, was a candidate at one time for County Treasurer, and served as Camden's police and fire  commissioner in the mid-1920s under Mayor Victor King. He also was charter member of the Camden Lodge of the Loyal Order of Moose. 

By 1920 John J. Welsh was a widower. He was then living at 583 Line Street with his sons Edward, 38, and Frank, 26; Frank's wife Bessie, and grandchildren John and Robert. His sons both were working as carpenters in his construction business.  He and Edward later moved to 433 Chambers Avenue, the home of his younger brother Michael Welsh, where the two resided at the time of the 1930 Census. This address had previously been the residence of Alfred White, Camden City Clerk from 1923 to 1927. He had established his business by then at 529 Washington Street.

John Welsh stayed active in his business into the 1930s, when illness finally confined him to his bed. He passed away on August 29, 1936 and was buried at Calvary Cemetery. His son, Frank J. Welsh, remained in business at 529 Washington Street as late as 1947, and lived in Audubon NJ for many years, before passing in 1978.