The empirical assessments of the traditional teaching approach of lecturing in the undergraduate classroom indicate its ineffectiveness in the learning process. This traditional pedagogy has been identified as one of the major reasons adversely impacting student engagement and motivation, especially in the science, technology, engineering and mathematics (STEM) fields. Research on learning provides strong evidence that active-learning can have a positive impact on student learning outcomes. The biggest challenge with incorporating active-learning strategies in the classroom is the time constraint of the traditional class period. One of the approaches that is finding increasing acceptance among educators is the use of the flipped classroom. This paper shares details of the impact of active-learning on academic achievement of students from groups underrepresented in STEM in introductory mathematics and aerospace engineering courses. The results indicated that the performance of students who took the courses with the active learning improved.