  We report on the final two days of a multiwavelength campaign of Sgr A*
observing in the radio, submillimeter, infrared, and X-ray bands in July 2019.
Sgr A* was remarkably active, showing multiple flaring events across the
electromagnetic spectrum. We detect a transient $\sim35$-minute periodicity
feature in Spitzer Space Telescope light curves on 21 July 2019. Time-delayed
emission was detected in ALMA light curves, suggesting a hotspot within the
accretion flow on a stable orbit. On the same night, we observe a decreased
flux in the submillimeter light curve following an X-ray flare detected by the
Chandra X-ray Observatory and model the feature with an adiabatically expanding
synchrotron hotspot occulting the accretion flow. The event is produced by a
plasma $0.55~R_{\text{S}}$ in radius with an electron spectrum $p=2.84$. It is
threaded by a $\sim130$ Gauss magnetic field and expands at $0.6\%$ the speed
of light. Finally, we reveal an unambiguous flare in the infrared,
submillimeter, and radio, demonstrating that the variable emission is
intrinsically linked. We jointly fit the radio and submillimeter light curves
using an adiabatically expanding synchrotron hotspot and find it is produced by
a plasma with an electron spectrum $p=0.59$, $187$ Gauss magnetic field, and
radius $0.47~R_{\text{S}}$ that expands at $0.029c$. In both cases, the
uncertainty in the appropriate lower and upper electron energy bounds may
inflate the derived equipartition field strengths by a factor of 2 or more. Our
results confirm that both synchrotron- and adiabatic-cooling processes are
involved in the variable emission's evolution at submillimeter and infrared
wavelengths.
