The Philippines was under the colonial rule of the United States from 1898 to 1946. With the American-Spanish War of 1898, the US had emerged as the new colonial ruler, driving out Spanish forces. For approximately half a century, the Philippines experienced a variety of European values and institutions under US rule. Their political and administrative systems, as well as education, were directly influenced by the US, who adopted multiple institutions from their homeland to rule and control their colonies. Conversely, the citizens of the Philippines ceaselessly argued for the just cause of “absolute independence.” Independence movements led by the people’s leaders were maximized with the development of political parties in the Philippines. Unlike the independence movements of Korea, they were organized by leaders residing in the Philippines, rather than in foreign countries. In other words, those organizations were active within the political institutions transplanted by the US. The legislative branch (parliament) was established as one of these colonial political institutions and, as they could become members of parliament, the people’s leaders were able to organize independence movements from within parliament actively. The purpose of this study is to explore the patterns and significance behind “the establishment and changes in the Philippines legislative branch (parliament)” and the “role of the cause for absolute independence,” which was one of the main objectives of parliamentary activities in the Philippines. In other words, this study aims to gain an understanding of the major institutions and organizations from which leaders of the independence movement pursued their activities under US rule. Moreover, it seeks to identify the characteristics of a series of movements that aimed for ultimate independence. The Philippines legislative branch was established and modified in many ways during US rule. While the establishment and changes themselves are significant, this study wishes to emphasize the legislative’s role as the key institution around which political movements were organized to pursue absolute independence for the Philippines.