Although many instructors are now using simulations and other experiential pedagogies in their classrooms, the effectiveness of such tools has generally not been examined in a systematic way. In this paper, we assess the effectiveness of a simulation of the legislative process in the U.S. Senate as a tool for teaching college students about the workings of the American political system. We used pre- and post-course surveys in two "Introduction to American Government" courses, one of which utilized traditional teaching methods, such as lectures and tests, and one of which supplemented these traditional methods with an online simulation. We compare the changes in political knowledge and attitudes within groups but focus on the differences and similarities between the "control" and "experimental" groups. We find that simulations can be an effective tool for civic education, but that their objectives must be clear and expectations should be reasonable. Students who participated in the simulation gained considerable knowledge of the legislative process compared to their peers in the traditional course, and their levels of cynicism decreased. (Contains 1 figure, 3 tables and 6 notes.)