This lesson introduces students to the Home Owners Loan Corporation (HOLC) maps of the 1930s and 40s, encouraging them to consider what qualities make a good neighborhood and in what ways those qualities can and can’t be measured. The legacy of redlining is also addressed with supplemental resources that explain the persistent disinvestment that resulted from the anti-Black and anti-immigrant bias accepted by the banking and real estate sectors at the time and the ways discrimination in these sectors continues today.