There are a number of arguments in favor of immigration that specifically apply to the United States of America. Note that the overall case for open borders is universal employs fairly country-independent arguments. Thus, these US-specific arguments can be thought of as additional arguments that support free migration into the United States, over and above the general case.

Pragmatic benefits

• Immigration economically benefits Americans
  • Claims that immigration reduces the wages of Americans are generally false or overexaggerated
• Immigrants are law-abiding and upright citizens
  • Allegations of immigrant criminality are also false or overstated
  • Suggestions of links between immigration and terrorism are categorically false
• Immigrants come to work, not claim welfare benefits

Philosophical arguments

• The collective property rights argument used to justify arbitrary immigration restrictions is anti-capitalist and anti-American
• Freedom of movement is a fundamental human liberty and it would be anti-liberty to restrict migration
• The government lacks sufficient knowledge to properly restrict immigration without causing undue harm, and thus immigration restrictions would undermine the rule of law

Tradition/precedent argument

From its founding until about 1921 (with some notable exceptions such as the Chinese Exclusion Act, which was deeply flawed), the United States of America had practically open borders. In fact, the United States had no federal laws restricting immigration until 1875. Even when some restrictions were put in place, such as for immigrants arriving by sea at Ellis Island, the rejection rate was ~2%.

With this policy of open borders, the United States expanded greatly in population and led the world in terms of increases in its standard of living and increases in per capita income. This historical success lends support to the idea that assimilating new waves of immigrants will be possible for the United States and will lead to greater prosperity for the nation.

References:

• The Golden Age of Migration, a blog post by Bryan Caplan refers to the book Exceptional People: How Migration Shaped Our World and Will Define Our Future.
• Did Mercantilism Promote Economic Growth in the U.S.?, a blog post by Donald Boudreaux that references the papers Tariffs, Immigration, and Economic Insulation: A New View of the U.S. Post-Civil War Era by Cecil E. Bohanon and Tariffs and Growth in Late Nineteenth Century America by Douglas Irwin to argue that the rapid growth that the United States experienced in the nineteenth century was largely a result of free immigration, and not due to the mercantilist economic policies followed during that time.

For counter-arguments offered by restrictionists to this tradition/precedent-based line of reasoning, see the then versus now page.

Constitution/originalism argument

Some arguments have been made from a constitutional originalist perspective that the US government is not authorized to restrict migration for arbitrary reasons.

• Immigration and the US Constitution by George Mason University law professor Ilya Somin in a guest post for the Open Borders blog, March 18, 2013. The post is one of the top Google Search results for “what does the constitution say about immigration” — a search term that became quite popular around the time of US President Barack Obama’s November 2014 deferred action announcement.
• The Constitution, Citizenism, and the Natural Right of Migration by Chris Hendrix on the Open Borders blog, November 13, 2012.

American exceptionalism argument

The United States of America is one of the few countries where an immigrant can become American. It’s a unique and exceptional characteristic of US culture that is worth preserving.

General references for US-specific pro-immigration arguments

For more information and web resources, check out the pro-immigration and migration information web resources page.

• Cato Institute immigration page lists the case made by scholars at the Cato Institute in favor of more free immigration.
• Alex Nowrasteh used to work at the Competitive Enterprise Institute exclusively on immigration issues, with a particular focus on the United States.