Increasing numbers of mathematics educators, policy makers, and researchers believe that algebra should become part of the elementary education curriculum. Such endorsements require careful research. This paper presents the general results of a longitudinal classroom investigation of children's thinking and representations over two and a half years, as they participate in Early Algebra activities. Results show that 3rd and 4th grade students are capable of learning and understanding elementary algebraic ideas and representations as an integral part of the early mathematics curriculum. (Contains 1 footnote.) [For complete proceedings, see ED500860.]