Great advancements have been made in the area of plant breeding and genetics since the turn of the century. Many of these advancements stem from research in maize, which is an important global crop. This paper seeks to answer the question: How has the study and mapping of genetic variation in maize germplasm at a genome-wide level facilitated the development of markers for maize breeding? Since the first types of molecular markers were identified, their utility and functionality has increased greatly to the plant breeding community. Functional Markers (FMs) are polymorphic markers located within a gene whose function has been proven to regulate a trait of interest. Maize breeders are gaining more access to published FMs, which are being created based on an increased understanding of gene function coming from gene cloning and mutant analyses. They can use these markers to increase the efficiency of their breeding programs through marker-assisted selection (MAS), which has revolutionized traditional breeding methods. Current research and literature have been reviewed surrounding sequencing technologies, the maize genome, and specific gene sequences and their functions. Also reviewed are examples of how these technologies have aided the development of Functional Markers in maize.