The Moon is the sole known locality of exposed high-titanium (high-Ti) basalts in the solar system, but their occurrence has implications for the early evolution of the terrestrial planets. High-Ti basalts derive from partial melts of cumulates in the lunar upper mantle. The ilmenite, clinopyroxene, and olivine cumulates from which these basalts form are late-stage products of crystallization of the lunar magma ocean, a planetary-scale melting event that also likely occurred early on in the evolution of Venus, Mercury, the Earth and Mars. Fortunately, despite the ancient nature of mare volcanism, pristine high-Ti basalts are preserved on the relatively inert lunar surface, and the lunar sample collection contains abundant high-Ti basaltic material. Crystals are quantifiable components of the basaltic system, and are a record of the compositional and temporal history of magmatic evolution. Complementary techniques of textural and in-situ trace element geochemical analyses comprise the crystal stratigraphy method used to investigate this history. I use crystal size distributions and spatial distribution profiles to identify crystal populations and quantitatively evaluate rock textures. I use EPMA and LA-ICP-MS analysis of major crystallizing phases to identify processes affecting evolving magmas. I first show that LA-ICP-MS can determine accurate and precise trace elements for ilmenite, which is a major crystallizing phase in high-Ti basalts. The Taurus-Littrow Valley on the Moon contains high-Ti basalts from multiple distinct magmatic source regions. I propose multiple flow events of some regions were sampled during the Apollo missions, and magma partially crystallized for short residence times at shallow depths. Textural characterization of a high-Ti olivine cumulate shows no other samples experienced crystal accumulation. Finally, I investigate two rocklets found in the lunar highlands that were recently classified as basalts. I confirm their basaltic nature, extending the mare CSD database to include picritic basalt and Luna 24-type basalt. This dissertation marks the first application of the crystal stratigraphy method to the investigation of high-Ti basalts.