In this article, we present the results from a longitudinal examination of the impact of a "Standards"-based or reform mathematics curriculum (called CMP) and traditional mathematics curricula (called non-CMP) on students' learning of algebra using various outcome measures. Findings include the following: (1) students did not sacrifice basic mathematical skills if they are taught using a "Standards"-based or reform mathematics curriculum like CMP; (2) African American students experienced greater gain in symbol manipulation when they used a traditional curriculum; (3) the use of either the CMP or a non-CMP curriculum improved the mathematics achievement of all students, including students of color; (4) the use of CMP contributed to significantly higher problem-solving growth for all ethnic groups; and (5) a high level of conceptual emphasis in a classroom improved the students' ability to represent problem situations. (However, the level of conceptual emphasis bears no relation to students' problem solving or symbol manipulation skills.) (Contains 12 tables and 3 figures.)