We report broadband UBV and/or BVR _ { C } I _ { C } CCD photometry for a total of 1857 stars in the thick-disk and halo populations of the Galaxy .
The majority of our targets were selected as candidate field horizontal-branch or other A-type stars ( FHB/A , N = 576 ) , or candidate low-metallicity stars ( N = 1221 ) , from the HK and Hamburg/ESO objective-prism surveys .
Similar data for a small number of additional stars from other samples are also reported .

These data are being used for several purposes .
In the case of the FHB/A candidates they are used to accurately separate the lower-gravity FHB stars from various higher-gravity A-type stars , a subsample that includes the so-called Blue Metal Poor stars , halo and thick-disk blue stragglers , main-sequence A-type dwarfs , and Am and Ap stars .
These data are also being used to derive photometric distance estimates to high-velocity hydrogen clouds in the Galaxy and for improved measurements of the mass of the Galaxy .
Photometric data for the metal-poor candidates are being used to refine estimates of stellar metallicity for objects with available medium-resolution spectroscopy , to obtain distance estimates for kinematic analyses , and to establish initial estimates of effective temperature for analysis of high-resolution spectroscopy of the stars for which this information now exists .