  We present spectroscopic data for 16369 stellar targets within and/or toward
38 dwarf spheroidal galaxies and faint star clusters within the Milky Way halo
environment. All spectra come from observations with the multi-object,
fiber-fed echelle spectrographs M2FS at the Magellan/Clay telescope or
Hectochelle at the MMT, reaching a typical limiting magnitude G < 21. Data
products include processed spectra from all observations and catalogs listing
estimates -- derived from template model fitting -- of line-of-sight velocity
(median uncertainty 1.1 km/s) effective temperature (234 K), (base10 logarithm
of) surface gravity (0.52 dex in cgs units), [Fe/H] (0.38 dex) and [Mg/Fe]
(0.24 dex) abundance ratios. The sample contains multi-epoch measurements for
3720 sources, with up to 15 epochs per source, enabling studies of intrinsic
spectroscopic variability. The sample contains 6078 likely red giant stars
(based on surface gravity), and 4494 likely members (based on line-of-sight
velocity and Gaia-measured proper motion) of the target systems. The number of
member stars per individual target system ranges from a few, for the faintest
systems, to ~ 850 for the most luminous. For most systems, our new samples
extend over wider fields than have previously been observed; of the likely
members in our samples, 823 lie beyond twice the projected halflight radius of
their host system, and 42 lie beyond 5 Rhalf.
