The purpose of this historical review was to trace the credible leadership construct of trustworthiness, integrity, honesty, and consistency in leadership theory development during the last 100 years in the United States. Theory focus, key U.S. pivotal events, and follower importance influenced the construct's occurrence in leadership theory. When trait theory dominated leadership theory, an amplified importance of leader credibility characteristics was present in theory development. When leadership theory emphasized leader-follower relationships, with followers' perceptions playing a leading factor in effective leadership, traces of credible leadership in theory development was also more prevalent. Leadership theory development, particularly the credible leadership construct, and the United States' pivotal events mutually shaped one another throughout the century. The leadership credibility factor in theory increased or decreased based on the economic, social/cultural, political, and educational contexts that coincided with each decade of theory advancement. The presence of leader credibility in theory development waxed and waned during the 20th century. Its absence in theory occurred at the beginning and middle part of the 20th century. During the 1910s, leadership theory concentrated on heredity as the defining factor in leadership development. The credible leadership construct was not of importance then. During the 1950s and throughout most of the 1960s, the credible leadership construct was absent. Theory development during that time predominately focused on leader behavior and style, with minimal attention to credibility in leaders and follower importance. [The dissertation citations contained here are published with the permission of ProQuest LLC. Further reproduction is prohibited without permission. Copies of dissertations may be obtained by Telephone (800) 1-800-521-0600. Web page: http://www.proquest.com/en-US/products/dissertations/individuals.shtml.]