This investigation of twentieth century trends in mathematics education includes the survey of existing literature and questionnaires conducted with retired and active Texas teachers. Historical events, trends in curriculum, instruction, learning theories, and contradictions of twenty-year periods are delineated. Questionnaire responses are tabulated along the same periods and vignettes of typical classrooms are drawn from the data. Results of the survey show the impact of societal forces on mathematics curricula, a continued downward expansion of content into lower grades and expanding knowledge of learning processes. A unified mathematics curriculum, classroom-related learning theory research, and further development of team-teaching are postulated as future trends. Recommendations include further examination of trends through isolation of other variables such as region and ethnicity.