H-1B
The H-1B program brings into the United States hundreds of thousands of workers from foreign nations at lower wages and restrictions on job mobility. This program keeps real income for Americans from increasing, particularly in high-tech fields.
There are conceptual similarities between the H-1B program and the unsuccessful indentured servant program used in colonial Virginia, particularly Jamestown, in the early 1600s. But there are no shortage of American workers today, while there was in Jamestown in 1607, so the H-1B program is little more than the enrichment of large companies at the expense of American workers.
Large companies like Microsoft push hard for the H-1B program, and for expanding it, despite its negative effect on American workers.