Supposedly, Jerry was intrigued by the story of a troubled soul who is put to rest by a traveler. The spirit then repays the favor by helping the traveler with his own quest.
The Grateful Dead were a symbol of the 1960s counterculture. Though they never achieved mainstream commercial success, their legion of Deadheads followers brought them financial success.
They are forever part of the Haight-Ashbury, San Francisco scene, where they regularly played at Ken Kesey’s acid tests.
In their earliest incarnation, they were a jug band/country/blues band, which they returned to to some degree in their acoustic American Beauty/Workingman's Dead period. Over their 40-year career, they played many musical genres including rock, folk, R&B, jazz, and psychedelic.
They are best known as a live band and toured almost continually during the 60s and early 70s. (There are many more live recordings - legitimate and bootleg - than studio releases.)
It's strange to think of the Dead having a "greatest hits" album since they never sought out commercial success, but they did hit the charts in the late 80s with “Touch of Grey.”
The band essentially ended with the death of Jerry Garcia in 1995, though members of the band still tour and release tracks as part of other ventures. Former members of the band, along with other musicians, toured as The Other Ones in 1998, 2000, and 2002, and as The Dead in 2003, 2004, and 2009. In 2015, the four surviving core members marked the band's 50th anniversary in a series of concerts in Santa Clara, California, and Chicago that were billed as their last performances together. There have also been several spin-offs featuring one or more core members, such as Dead & Company, Furthur, the Rhythm Devils, Phil Lesh and Friends, RatDog, and Billy & the Kids.