Math classes do not usually offer students an opportunity to learn about the diversity within the field of mathematics. As a result, students tend to hold inaccurate, negative perspectives about diversity in the world of mathematics and many may not feel a sense of belonging in the classroom when they do not see themselves reflected in the curriculum. The relationship between history and mathematics should be explored as one way to correct inaccurate views about what defines a mathematician and what the benefits are of studying mathematics and its relevance in daily life. One of the teaching practices that can support diversity and inclusion in the mathematics classroom is exposing students to a diverse group of mathematicians. In this study, we investigated the effects of using this teaching practice on creating an inclusive classroom. The participants in this study were 36 undergraduate students enrolled in a Precalculus course. Data were collected using a pre- and post-test tool and analyzed both quantitatively and qualitatively. An in-depth analysis through close comparisons between students' responses in the pre and post-tests. The results indicated that participants gained a new knowledge from the treatment (the historical projects) that expanded their horizons about mathematics diversity. [For the full proceedings, see ED630893.]