While the word “pedagogue” may evoke a vision of an instructor who is dogmatic and set in his own ways, the word descends from Greek origins: ped “child” + agogos “leader.” A pedagogue is, by definition, literally the servant who escorts the child to and from school – the “pedagogue” accompanies the student on the journey for knowledge. True to this definition, Douglas Campbell is model pedagogue – one who gently guided his countless students throughout their musical journeys. As Professor of Music (Horn) at Michigan State University for 45 years, and Horn Instructor at Interlochen Arts Camp for 25 years, Campbell was a significant influence on many developing hornists. Following their study with him, Campbell's students eventually won orchestral and college teaching positions across the United States and throughout the world. Having influenced an extraordinary number of horn students during his tenures at Michigan State University and Interlochen Arts Camp, Douglas Campbell's life and career serve as an excellent example of contemporary horn pedagogy in the United States. This dissertation provides a detailed biography of Douglas Campbell and provides evidence of his contributions to American horn pedagogy, while documenting Campbell’s performing career with the Richards Quintet, which toured the United States, Canada, and China. Additionally, compositions written for or commissioned by Campbell (Harmonielehre: Variations for Solo Horn [1996] and Epitaph [2012]) are discussed, to illustrate Campbell's influence on solo literature for the horn.