Congress passed its first naturalization law 228 years ago on March 26, 1790. The Naturalization Act of 1790 was the most open naturalization law in the world at the time, allowing free white persons of good character to naturalize after two years of residence in the country and one year of residence in a particular state. Denying citizenship to American Indians, free blacks, indentured servants, and others who did not count as free white persons was a great injustice, but the 1790 Act was an improvement over other countries at the time that also limited naturalization based on gender, skill, or religion in addition to race. Although the Naturalization Act of 1790 did place some restrictions on who could become a citizen, it placed no restrictions on who could enter the United States. The Supreme Court largely corrected Congress’ error in 1898 in its United States v. Wong Kim Ark decision when it ruled that children of immigrants, including non-whites, were also citizens if they were born in the United States.

The Western world had a long legal, social, and ethical tradition of openness to immigrants and naturalization that culminated in some of the best portions of the American immigration system. Hillsdale College history professor Bradley J. Birzer wrote a wonderful essay for The American Conservative in January that showed that our civilizational heritage is replete with relatively open borders and the unencumbered movement of people across them with few practical restrictions, with the United States as a recent inheritor of such thought. Although Greeks and Romans both had liberal migration systems, there were important distinctions between Roman and Greek practices of naturalization and citizenship. The American Founding Fathers decidedly favored a model close to that of the Romans over that of the more restrictive Greeks.

Archaeologist John R. Hale of the University of Louisville wrote, “[u]nlike many of its neighbors, Athens eagerly welcomes foreigners from overseas, whether Greek or ‘barbarian,’ and encouraged them to settle down as residents. So tolerant did the Athenians become that they permitted foreign merchants to build shrines to their own gods within the walls of the Piraeus.” Resident foreigners in Athens were called metics and had to pay a special tax called a metoikion. Metics could not own real estate or participate in politics but they could work, amass wealth, and be productive members of the Athenian economy. Athens was the seat of ancient philosophy for several centuries, but many of its most famous philosophers were foreign-born including Aristotle, Anaxagoras, and Zeno. Aristotle and Cephalus, whose mansion Socrates visits at the beginning of The Republic, are two of the most famous metics.

The Athenian political leader Themistocles, whose policies were foremost responsible for Athenian wealth and power, convinced the city to create publicly-funded incentives to attract skilled craftsmen to the city. This is not too different from the mythological Theseus, the first king of Athens, who also encouraged the immigration of metics. After the defeat of Athens in the Social War, Xenophon suggested attracting more metics to the city to help rebuild its economy because they paid taxes but consumed few public benefits.

Athens’ open migration system was in stark contrast to its burdensome citizenship system: Only those born to Athenian parents were citizens. The Assembly in Athens extended citizenship to metics and freed slaves during military emergencies or to larger groups of people for strategic advantage but mainly did so on an individual basis by a vote of the assembly, often after a foreigner served in the military and distinguished himself in battle.

Rome encouraged both immigration and naturalization. Whereas Athens allowed foreigners to live in the city, Rome actually extended citizenship to them and gradually to conquered peoples. It even allowed freed slaves to gain Roman citizenship which occurred in Athens only during military emergencies that required a levee en masse. These unique Roman policies created the most ethnically diverse polity prior to the modern world and allowed people to be citizens of their city of birth and of Rome. The immigration, citizenship, and manumission policies that created Rome are as ancient as the two mythical foundings of the state, according to historian Mary Beard.

The first myth was that of the Trojan refugee Aeneas who founded Rome after displacing the aborigines who originally inhabited the area. According to this tale, the Romans were always foreigners and had no immemorial tie to the land itself. The second myth is that Romulus, who, after founding the city, “declared Rome an asylum and encouraged the rabble and dispossessed of the rest of Italy to join him: runaway slaves, convicted criminals, exiles, and refugees. This produced plenty of men.” Those men then abducted and raped Sabine women in a horrific ruse that is part of the city’s foundation myth. As disgusting as half of that foundation myth is, Romans could never claim to have a blood-based identity due to the foreign origins of the original inhabitants of the city.

As Rome expanded, they gradually extended citizenship to both allies and conquered peoples as a means of increasing the manpower available for military service and rewarding loyalty. Indeed, later restrictions on the extension of Roman resulted in one of the strangest civil wars in history when allied cities rebelled in order to gain naturalization. Republican Rome tightened its citizenship rules after the Second Punic War ended in 202 BC and severely curtailed its previous open-door immigration and naturalization policy. The new restrictions led to an uprising in cities who wanted Roman citizenship. To quiet the unrest, Rome finally reinstated the older naturalization and immigration rules after punishing the ringleaders of the revolt.

A steady stream of immigrants arrived in Rome for centuries with the aid of some famous litigators like Cicero. Many famous Roman families were the descendants of immigrants, including the Julii from Alba Longa, the Coruncanii from Camerium, and the Porcii from Tusculum. Attius Clausus immigrated to Rome in 504 BC from Regillum, eventually becoming a senator and consul. His descendant was the famous Emperor Claudius, who extended Roman citizenship to many Gauls by appealing to the pro-citizenship and immigration mythology of the Roman foundation myth. As Claudius noted, “Our founder Romulus was so wise that he fought as enemies and then hailed as fellow-citizens several nations on the very same day.” In 212 AD, the emperor Caracalla extended citizenship to every free male inhabitant of the Roman Empire, erasing the legal differences between conquerors and conquered. Over the centuries, Roman emperors began to hail from outside of Italy. The emperor Septimus Severus was from Africa, Trajan and Hadrian were both from conservative Spain, Phillip was from Arabia, and almost 20 other Eastern and Western emperors were from the Balkans.

The Founders complained about King George III’s restrictions on naturalization and subsequently created the most liberal naturalization system in the world at the time, and understood that open immigration and liberal naturalization were enormously advantageous to the growing republic. Any comparison to the Classical world is strained but, to the extent which we can compare the current immigration and naturalization system of the United States to the past, the American government clearly borrowed more from the more open Roman system than from the more closed Athenians.