We present a fundamental study of the sintering behavior of tantalum carbide powders during spark plasma sintering. The powders were produced by a solvothermal synthesis method and characterized using dynamic light scattering, X-ray diffraction, and microscopy. Spark plasma sintering of these powders with additions of carbon, hafnium carbide, zirconium carbide, and tungsten carbide is performed. Evolution of the microstructure is evaluated with an emphasis on minimizing grain size while maximizing density. Correlations between the powder crystallite size and particle size, with respect to final sintered grain size, are made. The grain boundary structure and defects in the material are determined. Preliminary investigations of the electrical, thermal, and mechanical properties are also evaluated and include measurement of electrical conductivity, thermal conductivity, oxidation behavior, Young’s modulus, shear modulus, and Poisson's ratio. This study has implications for the processing of carbide materials using fast sintering techniques.