  Supergiant shells (SGSs) are the largest interstellar structures where heated
and enriched gas flows into the host galaxy's halo. The SGSs in the Large
Magellanic Cloud (LMC) are so close that their stars can be resolved with
ground-based telescopes to allow studies of star formation history. Aiming to
study the star formation history and energy budget of LMC 4, we have conducted
a pilot study of the cluster NGC 2021 and the OB associations in its vicinity
near the south rim of LMC 4. We use the Magellanic Cloud Photometric Survey
data of the LMC to establish a methodology to examine the stellar population
and assess the massive star formation history. We find a radial procession of
massive star formation from the northwest part of the OB association LH79
through NGC 2021 to the OB association LH78 in the south. Using the stellar
content of NGC 2021 and the assumption of Salpeter's initial mass function, we
estimate that $\sim$4 supernovae have occurred in NGC 2021, injecting at least
$4\times10^{51}$ ergs of kinetic energy into the interior of LMC 4.
