What year did punk rock come?

Answer 1

There is no one answer to this, as artists such as The Stooges, Patti Smith, MC5, and The New York Dolls incorporated elements of punk into their music, but are generally regarded as "proto punk," meaning that they influenced the punk genre, but came before it and are not a part of it.

The Ramones, formed in 1974, are widely regarded as the first American punk band.
The Sex Pistols, formed in 1975, are considered the first British punk band.

Answer 2

I would say 1978. The first two weeks of that year, The Sex Pistols toured America and then promptly broke up. That was the year that punk exploded into the mass consciousness, becoming a fully-fledged youth movement in both the U.S. and the U.K.

Answer 3

It developed between 1974 and 1976.