Redlined neighborhoods were left vulnerable to racial disparities in environmental exposures and associated poor health outcomes. This racially motivated practice began in the 1930s with the creation of the Homeowners Loan Corporation (HOLC) by the federal government. This thesis will use an ecological study approach to study inequities in health outcomes associated with historical redlining using the rate of pediatric asthma-related emergency room (AER) visits as a proxy to measure asthma burden.