When the Mechanics' Institute closed in 1890, the Natural History Society of New Brunswick acquired the collection and the museum was moved, first to the then new Market Building then, in 1906, to 72 Union Street.Under the care of its curator and later director, the entomologist Dr. William McIntosh, the museum's collections and activities expanded until a new building was essential.The Collections Centre, the Archives and Research Library, and the Head Office continued to be situated at the Douglas Avenue location.[4] In July 2023, it was announced that a revitalized New Brunswick Museum would be located in its original, 1934 home on Douglas Avenue in Saint John.In December 2023, The New Brunswick Museum announced it had secured a new research and collections centre on Saint John's west side, as it prepared to break ground in 2024 on its estimated $150-million new home on Douglas Avenue.