  We present followup optical g', r', and i', imaging and spectroscopy of
serendipitous X-ray sources detected in 6 archival Chandra, images included in
the Chandra, Multiwavelength Project (ChaMP). Of the 486 X-ray sources detected
between 3e-16 and 2e-13 (with a median flux of 3e-15 erg cm-2 s-1, we find
optical counterparts for 377 (78%), or 335 (68%) counting only unique
counterparts. We present spectroscopic classifications for 125 objects,
representing 75% of sources with r<21 optical counterparts (63% to r=22). Of
all classified objects, 63 (50%) are broad line AGN, which tend to be blue in
g-r colors. X-ray information efficiently segregates these quasars from stars,
which otherwise strongly overlap in these SDSS colors until z>3.5. We identify
28 sources (22%) as galaxies that show narrow emission lines, while 22 (18%)
are absorption line galaxies. Eight galaxies lacking broad line emission have
X-ray luminosities that require they host an AGN (logL_X>43). Half of these
have hard X-ray emission suggesting that high gas columns obscure both the
X-ray continuum and the broad emission line regions. We find objects in our
sample that show signs of X-ray or optical absorption, or both, but with no
strong evidence that these properties are coupled. ChaMP's deep X-ray and
optical imaging enable multiband selection of small and/or high-redshift groups
and clusters. In these 6 fields we have discovered 3 new clusters of galaxies,
two with z>0.4, and one with photometric evidence that it is at a similar
redshift.
