Touch-Tone was developed in the late 1950's.
It was promoted at the Bell System Pavilion at the 1962 Seattle World's Fair, as can be seen in this fascinating short film, "21st Century Calling" (a bonus feature on the DVD of the Mystery Science Theatre 3000 episode, "The Killer Shrews"). Other features promoted in the film include call forwarding and three-way calling.
Bell Labs officially announced Touch-Tone as a feature (PDF) in 1964.
Touch-Tone was rolled out to consumers in the 1980s as a feature which consumers had to pay extra for, even though it cost nothing more to provide. The SS7 electronic switching infrastructure costs were covered by consumer fees such as the monthly fee for Touch-Tone service, and then used to roll out new services to businesses, subsidized by consumers.
Time from innovation to deployment: over two decades.