Complex sentence: According to Robert Palmer, the first accounts of the ring shout come from the 1840s, the stamping and clapping in a circle described as a kind of "drumming" and seeming to to have arisen from the conversion of slaves to Christianity.
Split into simpler sentences: According to Robert Palmer, the first accounts of the ring shout come from the 1840s. The stamping and clapping in a circle was described as a kind of "drumming," and 19th-century observers associated it with the conversion of slaves to Christianity.