 By the late 1950s and early 1960s, industries were already making the choice to move to suburban locations along newly constructed highways, where land costs were lower.The construction of the elevated Northern Expressway portion of Interstate 93 in the 1970s segregated the uses on both sides of the highway and significantly reduced its access and visibility from the surrounding areas.In 1976, First National closed its operations, marking the end of Assembly Square as a major industrial employment center.