Final answer:
The Oneida Community was known for its practice of complex marriage and its pursuit of perfectionism under the leadership of John Humphrey Noyes.
Step-by-step explanation:
The Oneida Community was known for its radical social and religious practices, including the concept of complex marriage and striving for perfectionism. Founded by John Humphrey Noyes in Oneida, New York, the community aimed to create a utopian society based on the principles of self-control, communal love, respect, and the belief that humans can achieve a state of perfection. Despite its ambitious goals, the community ultimately dissolved in 1881, but its legacy as an example of a utopian religious community remains.