Being naturalized as a U.S. citizen was not an option for Korean and other Asian immigrants for a long time, purely due to their race. Under the Naturalization Act of 1790, the right to become a naturalized citizenship in the U.S. was restricted to “any alien, being a free white person”. After the Civil War, the Naturalization Act of 1870 extended the right to include “aliens of African nativity or to persons of African descent.” However, the naturalization laws throughout the 1800s and the early 1900s were silent on the eligibility of foreign-born Asians.
For the Chinese immigrants, the Chinese Exclusion Act of 1882 explicitly barred them from being naturalized.
Thus the phrase “aliens ineligible for citizenship” was often used as a catch-all term to refer to Asian immigrants, especially in legislations targeting them. For example, the Alien Land Law of 1913 that was passed by the California legislatures barred “aliens ineligible for citizenship” from purchasing real property or leasing agricultural land for more than three years.
This raises the question: how did Dr. Seo Jae Pil, the first Korean immigrant to the U.S., become a naturalized citizen in 1890? No one seems to know. Most courts concluded that Asians did not qualify as “free white person” although some sources state that the issue was debated and led to conflicting opinions. Perhaps Dr. Seo got lucky through a favorable court opinion or he could have qualified under a special exemption. A limited category of Asians were granted special rights to naturalize, such as foreign-born Asian spouses who were married to American soldiers were eligible to naturalize under the War Brides Act of 1947. However, in 1890, there seems to be no obvious exemption that would explain Dr. Seo’s citizenship.
Asian immigrants eventually gained the right to become naturalized, incrementally. In 1943, the Chinese became the first Asian group to have the right to naturalize when the Chinese Exclusion Act was repealed. The Filipinos and South Asians were allowed to be naturalized starting in 1946. For all other Asian immigrants, including Koreans, the right to become naturalized was finally a reality when the Immigration and Nationality Act of 1952 (aka McCarran-Walters Act) ended all race-based exclusion to naturalization.