In what year was it built

It was built in 1871.

From "Grand Central Deport" 1871 takes the name of "Grand Central Station" shortly after. Finally in 1913 after NY had banned the passage of steam locomotives and passing to electric trains it became "Grand Central Terminal"

This version of Grand Central Terminal, named after two previous stations that used to exist on the same land (1871-1900 and 1900-1910) , was built between 1910 and 1913, and opened on February 2, 1913.

Right - Originally Grand Central Depot https://www.grandcentralterminal.com/history/