  We present new Hubble Space Telescope Advanced Camera for Surveys imaging of
six positions spanning 5.8 kpc of the HI major axis of the Local Group dIrr NGC
6822, including both the putative companion galaxy and the large HI hole. The
resulting deep color magnitude diagrams show that NGC 6822 has formed >50% of
its stars in the last ~5 Gyr. The star formation histories of all six positions
are similar over the most recent 500 Myr, including low-level star formation
throughout this interval and a weak increase in star formation rate during the
most recent 50 Myr. Stellar feedback can create the giant HI hole, assuming
that the lifetime of the structure is longer than 500 Myr; such long-lived
structures have now been observed in multiple systems and may be the norm in
galaxies with solid-body rotation. The old stellar populations (red giants and
red clump stars) of the putative companion are consistent with those of the
extended halo of NGC 6822; this argues against the interpretation of this
structure as a bona fide interacting companion galaxy and against its being
linked to the formation of the HI hole via an interaction. Since there is no
evidence in the stellar population of a companion galaxy, the most likely
explanation of the extended HI structure in NGC 6822 is a warped disk inclined
to the line of sight.
