Seysey was a Native American chief who was involved in several negotiations regarding land.

The 1645 Indian deed for a tract of land on Long Island  which included Gouwanus and Coney Island is signed by him.   And in 1652 he signed the Indian deed for New Utrecht on Long Island.

See also:  Marechkawick: A Lenape Town, digital interactive at The Old Stone House in Brooklyn, 2021. Written by Kim Maier, Maggie Weber, and Dylan Yeats and designed by Moey Inc. with support from the Institute of Museum and Library Sciences Inspire! program.