In the 1800's, there was no John Muir Trail, nor was there any Sierra High Route. Theodore Solomons figured out the early routes. When the JMT was first built in the early part of the twentieth century, it went over Junction Pass. When Forester Pass was built, the trail went over it.
In the 1860's, the Brewer Party did some of the earliest recorded exploration of this area. They went from Mount Brewer, named after the leader, to Mount Tyndall and back. However, that is rough country, and if you are going against the grain, you better eat your Wheaties.