2-4, 1964: Two supposed incidents in the Gulf of Tonkin lead Johnson to seek congressional approval for direct U.S. involvement in Vietnam. March 8, 1965: First Marines land in Danang. Nov. 14-18, 1965: In the Ia Drang Valley, American troops fight their first large scale battles against the North Vietnamese Army.
I'd say they shut down, because most of the men enlisted as soldiers for the war. At that time/era, the workforce were mainly men, with the women staying home and taking care of the house.
