I have 2 friends from high school who climbed the FACE of Half Dome back in the 1950s. It took 2 days, as I remember, and they slept in rope slings on the face of the dome over night. They are both still alive today.
Got my doubts there. From Wikipedia:
The first attempt to climb it was made in 1954 by Dick Long, Jim Wilson, and George Mandatory. However, they only managed to climb 175 feet before retreating.
A more serious attempt to find passage up this cliff was made in 1955 by Jerry Gallwas, Don Wilson, Royal Robbins and Warren Harding. After climbing a mere 500 feet over five days, this party, too, retreated.
Gallwas and Robbins, armed with new chrome-molybdenum pitons made by Gallwas, recruited Mike Sherrick and set off on June 24, 1957, determined this time to finish the route. Over a period of five days, they encountered repeated obstacles and, using ingenuity and tenacity, they surmounted all these difficulties.
Five days after they had left the ground, they stood at the summit. Warren Harding had hiked up the backside of Half Dome via the hikers' trail for the occasion. He had been planning, along with Mark Powell and Bill "Dolt" Feuerer, to give the route another attempt, but had been beaten to it by the successful team. Nevertheless, Harding offered the triumphant team a warm congratulations.