As the Senate is mulling the details of a compromise immigration bill hammered together by the odd couple of Sens. Edward Kennedy and Jon Kyl, and as members of Congress hear from their constituents over the Memorial Day recess, it may be worthwhile to put the issue in historical context. For most of our history, the United States had no restrictions on immigration at all. I am told that my Canadian-born grandfather was a "nickel immigrant": He took the five-cent ferry from Windsor, Ontario, north to Detroit roundabout 1896. This situation resulted from America's strong demand for labor, coupled with...