The first entry is always the pin's source. Overall confidence is a weighted average of how firmly each reference supports the start and end times used above; a reference counts half as much for every 180 days older than the newest.
Wikipedia[3], the Henry Ford museum and Guinness World Records[2] all date the first Unimate installation to 1961, but none give a specific month or day.
Guinness World Records independently corroborates 1961 as the year of the first Unimate installation.
Wikipedia confirms the 1961 installation of the first Unimate at GM's Inland Fisher Guide plant in Ewing Township, New Jersey, matching the documentary's account almost verbatim.
Something missing or wrong? Say it in your own words: a link that backs this pin up, a different start or end date and why, or a fact it lacks or gets wrong. The AI checks it against this pin's sources, searches for better ones, and adds any page that backs you up. The pin's own sources still count most.