  In order to study the growth and evolution of circumstellar disks around
classical Be stars, we analyze optical time-series photometry from the KELT
survey with simultaneous infrared and visible spectroscopy from the APOGEE
survey and BeSS database for a sample of 160 Galactic classical Be stars. The
systems studied here show variability including transitions from a diskless to
a disk-possessing state (and vice versa), and persistent disks that vary in
strength, being replenished at either regularly or irregularly occurring
intervals. We detect disk-building events (outbursts) in the light curves of
28\% of our sample. Outbursts are more commonly observed in early- (57\%),
compared to mid- (27\%) and late-type (8\%) systems. A given system may show
anywhere between 0 -- 40 individual outbursts in its light curve, with
amplitudes ranging up to $\sim$0.5 mag and event durations between $\sim$2 --
1000 days. We study how both the photometry and spectroscopy change together
during active episodes of disk growth or dissipation, revealing details about
the evolution of the circumstellar environment. We demonstrate that photometric
activity is linked to changes in the inner disk, and show that, at least in
some cases, the disk growth process is asymmetrical. Observational evidence of
Be star disks both growing and clearing from the inside out is presented. The
duration of disk buildup and dissipation phases are measured for 70 outbursts,
and we find that the average outburst takes about twice as long to dissipate as
it does to build up in optical photometry. Our analysis hints that dissipation
of the inner disk occurs relatively slowly for late-type Be stars.
