When did Douglas Engelbart hold a demonstration known as "The Mother of All Demos" where he displayed the computer mouse and other inventions?

Douglas Carl Engelbart (January 30, 1925 – July 2, 2013) was an American engineer and inventor, and an early computer and Internet pioneer. He is best known for his work on founding the field of human–computer interaction, particularly while at his Augmentation Research Center Lab in SRI International, which resulted in creation of the computer mouse, and the development of hypertext, networked computers, and precursors to graphical user interfaces.

Under Engelbart's guidance, the Augmentation Research Center developed, with funding primarily from Defense Advanced Research Projects Agency (DARPA), the oN-Line System (NLS) to demonstrate numerous technologies, most of which are now in widespread use; this included the computer mouse, bitmapped screens, hypertext; all of which were displayed at "The Mother of All Demos" in 1968.