Short answers, pulled from the story.
Maharishi Mahesh Yogi founded the practice in 1955 after learning from his spiritual master Brahmananda Saraswati. He began publicly sharing the method that year before renaming it Transcendental Meditation in the late 1950s.
The movement claims to have five million followers globally as of recent estimates. Practitioners sit with their eyes closed and silently repeat a specific mantra for fifteen to twenty minutes twice each day through certified teachers who deliver the method via a standard seven-step course structure.
The movement gained significant momentum in the 1960s when celebrities including members of the Beatles and the Beach Boys started practicing the technique. By 1977, estimates suggested there were 900,000 participants worldwide with 600,000 located in the United States alone.
Maharishi Mahesh Yogi died in 2008 and leadership subsequently passed to neuroscientist Tony Nader. Related organizations such as the Global Country of World Peace and the David Lynch Foundation continue to promote the practice under this new direction.
Skeptics describe the Science of Creative Intelligence as pseudoscience because it promises abilities beyond natural laws while astrophysicist Carl Sagan labeled the Hindu doctrine behind TM as a form of pseudoscience. In 1979 the court case Malnak v Yogi determined the teachings were not a theistic religion but dealt with issues analogous to recognized religions.