Radio continuum observations were made of 59 IRAS sources that have 100 mum flux densities greater-than-or-equal-to 1000 Jy and far-infrared colors identified with ultracompact (UC) H II regions. Eighty percent were found to have associated compact radio sources. Seventy-five sources were detected at less than or similar 1'' resolution at 3.6 and 2 cm wavelengths, for which we provide contour plots and flux density distributions ranging from the radio to the near-infrared. Over half are unresolved and their morphologies undetermined. The remaining sources can be described by only five morphological classes, whose frequency of occurrence is consistent with that of the Wood and Churchwell survey. We calculate physical properties of the nebulae and show that they are consistent with UC photoionized regions. Alternative explanations are explored and found to be unlikely. The correlation of UC H II region positions with proposed spiral arms is examined and found to be well correlated only for the local spiral arm or spur.'' No obvious enhancement of UC H ii regions is apparent along the proposed Sagittarius and Scutum arms, probably because of inaccuracies in the kinematic distances. We find the latitude distribution of UC H II regions to lie in the range 0.5-degrees \b(FWHM)\ less-than-or-equal-to 0.8-degrees. No correlation between size and density of cometary and core-halo UC H II regions is found, consistent with the bow shock interpretation of these morphologies. Spherical and unresolved UC H II regions, however, appear to show a trend toward lower densities with increasing size, as expected for expanding H II regions. The observed ratios of far-infrared to radio flux densities of UC H II regions lie in the range 10(3) to greater than or similar to 10(5). By applying the results of model atmospheres, it is shown that this ratio depends on spectral type, ranging from approximately 10(3) for an O4 star to greater-than-or-equal-to 10(5) for a B3 star. We find that many of the UC H II regions in our sample must be excited by a cluster of stars, and most probably contain significant amounts of dust.
