Immigration Laws Regulating the Admission and Exclusion of Aliens at the Border [Updated May 19, 2020] [open pdf - 779KB]
From the Document: "Before the Coronavirus Disease 2019 (COVID-19) pandemic, the past few years had seen a marked increase in the number of apprehensions of non-U.S. nationals (aliens) at the border seeking to unlawfully enter the country. But entry restrictions at the U.S.-Mexico border in response to the COVID-19 pandemic have significantly reduced the number of alien apprehensions. Border closures and emergency measures in other countries have also restricted the ability of some 'migrant caravans' to reach the United States. Even so, there continues to be considerable attention concerning the treatment of aliens without legal immigration status who arrive at or near the U.S.-Mexico border."
CRS Legal Sidebar, LSB10150
Congressional Research Service: https://crsreports.congress.gov/