Mesmer was a German physician that was chased out of Vienna and then France because of his controversial medical theories about animal magnetism. He developed mesmerism techniques to help his patients and did alleviate some of their nervous disorders. Mesmer’s theories were later developed into the practice of modern day hypnotism. Many of the mediums in the spiritualist movement used trance speaking and automatic writing to access the other world.

A swedish scientist and inventor, Swendenborg received visions in middle age that eventually led to him devoting his time to transcribing the information he learned from his visions. He detailed the structure of the afterlife and gave a Christian view of reality that was not fundamentalist. He reportedly foretold catastrophes, including his own death. His writing was a major influence on the world view of the spiritualist movement.

Born in Upstate New York, he showed powers of clairvoyance at a young age. After being mesmerized he learned that he could see illnesses in parts of people’s bodies. He also had visions, one of which carried him forty miles from home. Afterward he claimed to have spoken with the spirit of Emanuel Swendenborg. He married the theories of Franz Anton Mesmer with Swedenborg, and published his theoretical work in 1847 (Just a year before the Fox sisters helped bring spiritualism into popular culture). This work, detailing the spiritual world (or “The Summerland”- as he coined it), criticizing elements of Christianity and advocating for Socialism had a major impact on the spiritualist movement. He even wrote in his journal: "About daylight this morning a warm breathing passed over my face and I heard a voice, tender and strong, saying: 'Brother, the good work has begun—behold, a living demonstration is born.' I was left wondering what could be meant by such a message." This was the last day of March, 1848, the same time which the Fox Sisters had begun their career as mediums.

- Leah Fox- (1813 – 1890)

-Margaretta (also called Maggie), ( 1833 – 1893)

-Catherine Fox (also called Kate) (1837 – 1892)

The younger fox sisters, Maggie and Kate reported the ability to commune with spirits after some rappings and knockings that happened in their home. They were sent to stay with their older sister, Leah in Rochester, where she monetized the controversy. Soon all three were acting as mediums and drawing large crowds. Their clients numbered some of the great social activists of the day including Henry Lloyd Garrison, the famous abolitionist and Robert Owen, the father of utopian socialism. Later in life, Maggie would denounce spiritualism and claim that she and her sisters had defrauded the public. She later recanted this claim, but the damage was done to much of the spiritualism movement.

This married couple were radical quaker reformers who were at the forefront of many social reform movements of this time. Living in Rochester, they were early adherents to spiritualism, and Isaac developed skills of his own as a medium. Amy had been at the Seneca Falls Woman's rights convention and had started her own economic rights for women convention a short time later. They were staunch abolitionists, feminists, and helped many escaped slaves get to Canada through their work as station managers of the Underground Railroad.