The James Webb Space Telescope (JWST) is the successor to the Hubble and Spitzer Space Telescopes. It has a broad scientific mission which includes spectroscopic studies of the epoch of reionization through observations of z>8 quasars. The Spitzer warm mission provides a unique opportunity to conduct an infrared survey of several hundred square degrees to a depth of several micro-Janskys, capable of finding quasars out to z=10. Deep JWST continuum spectroscopy of these quasars will establish the epoch and history of the Universe through detection of the Gunn-Peterson trough and/or Lyman-α damping wings. The statistics and luminosity function of high-z quasars will reveal the early history of accretion in the most extreme systems, providing insights in the role of black holes in galaxy evolution. Data obtained from an ultra-wide warm Spitzer survey will also be useful for other science, including studies of high-redshift galaxy clusters.