Control has frequently been discussed as beneficial to health, well-being, and coping with life's stressors. Nevertheless, control is not a unidimensional construct, and different aspects of control may be important at different points in the lifespan or under different life circumstances. In particular, control over one's environment and control over one's emotional responses to his or her environment may each be helpful; however, their unique contribution as well as their relationship to each other has not been fully investigated. Additionally, control is not a static construct; individuals may change in their feelings of control across days and years. The main objectives of this thesis were to investigate whether: 1) there is a daily relationship between environmental control and negative affect, 2) that relationship changes within participants across three waves of data spanning five years, 3) the age of the participant (when the study began) influences the daily relationship between environmental control and negative affect, and 4) global levels of emotion or environmental control influence individuals' relationship between daily environmental control and daily negative affect. Results indicated a significant daily relationship between environmental control and negative affect, and that this relationship decreased in strength across the 5 years. Global emotion control (but not global environmental control) moderated the daily relationship; specifically, on days of lower environmental control, individuals with higher global emotion control had lower negative affect than those with lower global emotion control. Age also moderated the daily relationship, with relatively older adults demonstrating lower negative affect on days of lower environmental control. Implications of these findings are discussed with regard to the compensatory nature of secondary control, aging, and intraindividual change and interindividual differences.