Yoga History, US timeline.

In 1920, Paramahansa Yogananda addressed a conference of religious liberals in Boston. He was sent by his guru, the ageless Babaji, to "spread the message of kriya yoga to the West."

In 1924, the United States immigration service imposed a quota on Indian immigration, making it impossible for Easterners to travel to America. Westerners were forced to travel to the East if they sought after yogic teachings.

Theos Bernard returned from India in 1947 and published Hatha Yoga: The Report of a Personal Experience. It was a major sourcebook for yoga in the 1950s and is still widely read today.

That same year, Indra Devi opened a yoga studio in Hollywood. Her three popular books had housewives from New Jersey to Texas standing on their heads in their bedrooms.

The person who introduced more Americans to yoga than any other in those days was Richard Hittleman, who in 1950 returned from studies in India to teach yoga in New York.

Yoga was established on the West Coast in the mid-'50s with Walt and Magana Baptiste's San Francisco studio. Walt's father had been influenced by Vivekananda, and Walt and Magana were students of Yogananda. The family yoga dynasty continues today with their children, Baron and Sherri.

In 1958, Indian-born Swami Vishnu-devananda, a disciple of Swami Sivananda Saraswati, arrived in San Francisco, sponsored by the artist Peter Max. His 1960 book, The Complete Illustrated Book of Yoga, became an essential guidebook for many practitioners. Dubbed by a colleague as "a man with a push," he founded the Sivananda Yoga Vedanta Centers, headquartered in Montreal, one of the largest networks of yoga schools in the world.

Meditation and yoga exploded across America in the early '60s, when an unassuming-looking yogi "came out of the Himalayas to spiritually regenerate the world." Maharishi Mahesh Yogi's Transcendental Meditation empire now claims 40,000 teachers and more than four million practitioners, with 1,200 centers in 108 countries.

In 1966 B.K.S. Iyengar's Light on Yoga was published in the United States, a book that is still considered to be the Bible of serious asana practice. In 1973, Iyengar was invited to Ann Arbor, Michigan to teach by Mary Palmer (mother of Mary Dunn). Nearly every Western teacher has been influenced by his emphasis on anatomical precision, many without even knowing it.

Swami Rama amazed researchers at the prestigious Menninger Foundation in 1970 when tests showed he could control his autonomic nervous system functions including heartbeat, pulse, and skin temperature.