  The origin of a regular, 600 pc-long arc of young stars and clusters in the
Constellation III region of the Large Magellanic Cloud is considered. The
circular form of this arc suggests that the prestellar gas was uniformly swept
up by a central source of pressure. In the center of the arc are six $\sim30$
My old A-type supergiant stars and a Cepheid variable of similar age, which may
be related to the source of this pressure. We calculate the expansion of a
bubble around a cluster of this age, and show that it could have triggered the
formation of the arc at the right time and place. Surrounding the central old
stars and extending well outside the young arc is the LMC4 superbubble and
giant HI shell. We show how this superbubble and shell could have formed by the
continued expansion of the 15 My old cavity, following star formation in the
arc and the associated new pressures. The age sequence proposed here was not
evident in the recent observations by Olsen et al. and Braun et al. because the
first generation stars in the center of the LMC superbubble are relatively
faint and scarce compared to the more substantial population of stars less than
15 My old that formed throughout the region in a second generation. These
considerations lead to an examination of the origin of the LMC4/Constellation
III region and other large rings in the LMC and other galaxies. Their size and
circularity could be the result of low galactic shear and a thick disk, with
several generations of star formation in their interiors now too faint to see.
