The article explores the history of immigration law practice in the U.S. from 1907 to 1940, focusing on the Immigrants' Protective League in Chicago. The League, led by women social workers, provided free legal counsel to thousands of immigrants facing tough immigration laws. They also conducted research, lobbied for better laws, and offered social services. The study shows that U.S. immigration laws have long been harsh and unpredictable, causing difficulties for migrants. The League played a key role in shaping the practice of immigration law by adapting to changing laws and helping immigrants navigate the system.