During the 1920s, the severest immigration restrictions in U.S. history, the 1924 Johnson-Reed Act and the national origins quota system, did not limit migration within the Americas. However, the Undesirable Aliens Act of 1929 (Blease’s Law) criminalized border crossing to limit the rights of Mexican immigrants. The segregationist and anti-immigrant Senator Coleman Livingston Blease (D-SC) led the legislative push to limit Mexican immigration. Disagreements between employers who depended on Mexican labor, particularly in agri-business, and restrictionists had prevented Congress from putting numeric limits on Mexican immigration. Blease proposed a solution criminalizing border crossings that occurred outside of official ports of entry. In 1929, Congress passed the new law, which made “unlawfully entering the country” a misdemeanor, punishable by up to a year’s imprisonment and fines, and returning to the United States after deportation a felony punishable by up to two years imprisonment and $1,000 in fines. Soon after passage of the Act, the U.S. economy entered the Great Depression and the federal government coerced Mexicans in the United States into repatriating by threatening penalties and conducting immigration raids targeting those who could not prove their legal status. By the end of the 1930s, U.S. attorneys had prosecuted more than 44,000 cases of unlawful entry almost entirely against Mexicans.
That (a) if any alien has been arrested and deported in pursuance of law, he shall be excluded from admission to the United States whether such deportation took place before or after the enactment of this act, and if he enters or attempts to enter the United States after the expiration of sixty days after the enactment of this act, he shall be guilty of a felony and upon conviction thereof shall, unless a different penalty is otherwise expressly provided by law, be punished by imprisonment for not more than two years or by a fine of not more than $1,000 or by both such fine and imprisonment.
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Sec. 2. Any alien who hereafter enters the United States at any time or place other than as designated by immigration officials or eludes examination or inspection by immigration officials, or obtains entry to the United States by a willfully false or misleading representation or the willful concealment of a material fact, shall be guilty of a misdemeanor and, upon conviction, shall be punished by imprisonment for not more than one year or by a fine of not more than $1,000, or by both such fine and imprisonment.
Sec. 3. An alien sentenced to imprisonment shall not be deported under any provision of law until after the termination of the imprisonment. For the purposes of this section the imprisonment shall be considered as terminated upon the release of the alien from confinement, whether or not he is subject to rearrest or further confinement in respect of the same offense.
Kelly Lytle Hernandez, “How Crossing the U.S.-Mexico Border Became a Crime.”
According to Blease’s bill, “unlawfully entering the country” would be a misdemeanor, while unlawfully returning to the United States after deportation would be a felony. The idea was to force Mexican immigrants into an authorized and monitored stream that could be turned on and turned off at will at ports of entry. Any immigrant who entered the United States outside the bounds of this stream would be a criminal subject to fines, imprisonment and ultimately deportation . . . .
With stunning precision, the criminalization of unauthorized entry caged thousands of Mexico’s “birds of passage.” By the end of 1930, the U.S. attorney general reported prosecuting 7,001 cases of unlawful entry. By the end of the decade, U.S. attorneys had prosecuted more than 44,000 cases.
According to the U.S. Bureau of Prisons, the vast majority of immigrants imprisoned for breaking Blease’s law were Mexicans. Throughout the 1930s, Mexicans never comprised fewer than 85 percent of all immigration prisoners. Some years, that number rose to 99 percent. By the end of the decade, tens of thousands of Mexicans had been convicted of unlawfully entering or reentering the United States. The U.S. Bureau of Prisons built three new prisons in the U.S.-Mexico border region: La Tuna Prison in El Paso, Prison Camp #10 in Tucson and Terminal Island in Los Angeles.