| 2024 |
Rosemont, Illinois (near Chicago) | The University of Chicago A (Illinois) | Cornell University A (Ithaca, New York) | University of Waterloo B (Ontario, Canada) | - |
| 2023 |
Rosemont, Illinois | Cornell University A | Brown University (Providence, Rhode Island) | University of Waterloo | - |
| 2022 |
Rosemont, Illinois | Leland Stanford Junior University A (California) | Georgia Institute of Technology (Atlanta) | Yale University B (New Haven, Connecticut) | - |
| 2021 |
Online | Columbia University A (New York, New York) | Brown University | Vanderbilt University (Nashville, Tennessee) | - |
| 2019 |
Rosemont, Illinois | Yale University A | Michigan State University (East Lansing) | University of Maryland-College Park B | - |
| 2018 |
Rosemont, Illinois | Yale University A | University of California-Berkeley B | The University of Chicago C | - |
| 2017 |
Rosemont, Illinois | University of Michigan-Ann Arbor A | University of Oklahoma (Norman) | University of California-Berkeley C | - |
| 2016 |
Rosemont, Illinois | The University of Chicago A | University of California-Berkeley A | The University of Chicago B | - |
| 2015 |
Atlanta, Georgia | University of Virginia (Charlottesville) | University of Maryland-College Park A | The University of Texas at Austin | - |
| 2014 |
Rosemont, Illinois | University of Virginia | Yale University | Harvard University (Cambridge, Massachusetts) | Valencia College A (Orlando, Florida) |
| 2013 |
Rosemont, Illinois | Yale University | The Ohio State University (Columbus) | Leland Stanford Junior University | Chipola College (Marianna, Florida) |
| 2012 |
Rosemont, Illinois | University of Virginia A | The Ohio State University A | Harvard University | Chipola College |
| 2011 |
Rosemont, Illinois | University of Minnesota-Twin Cities (Minneapolis) | Virginia Commonwealth University (Richmond) | Yale University | Chipola College A |
| 2010 |
Rosemont, Illinois | The University of Chicago A | University of Minnesota-Twin Cities A | Brown University | St. Charles Community College (Cottleville, Missouri) |
| 2009 |
Dallas, Texas | The University of Chicago A | University of Minnesota-Twin Cities A | The University of Chicago A | Northeast Alabama Community College (Rainsville) |
| 2008 |
St. Louis, Missouri | University of Maryland-College Park | Harvard University | Carleton College A (Northfield, Minnesota) | Valencia College |
| 2007 |
Minneapolis, Minnesota | The University of Chicago A | Carleton College A | University of Maryland-College Park | Valencia College A |
| 2006 |
College Park, Maryland | University of California-Berkeley | Williams College A (Williamstown, Massachusetts) | Leland Stanford Junior University | Broward College (Fort Lauderdale, Florida) |
| 2005 |
New Orleans, Louisiana | University of Michigan-Ann Arbor A | Virginia Commonwealth University | The University of Chicago | Coastal Alabama Community College - South District (Bay Minette) |
| 2004 |
St. Louis, Missouri | University of California-Berkeley | University of Illinois at Urbana-Champaign | University of California-Los Angeles | Valencia College |
| 2003 |
Los Angeles, California | The University of Chicago | Harvard University | University of California-Berkeley | Valencia College A |
| 2002 |
Chapel Hill, North Carolina | University of Michigan-Ann Arbor A | Princeton University A (New Jersey) | Yale University | Valencia College |
| 2001 |
St. Louis, Missouri | The University of Chicago | Princeton University A | University of Pittsburgh (Pennsylvania) | - |
| 2000 |
Boston, Massachusetts | University of Illinois at Urbana-Champaign | Princeton University A | Harvard University C | - |
| 1999 |
Ann Arbor, Michigan | The University of Chicago A | Carleton College A | Princeton University | - |
| 1998 |
Nashville, Tennessee | Leland Stanford Junior University | Swarthmore College (Pennsylvania) | Harvard University | - |
| 1997 |
Philadelphia, Pennsylvania | The University of Chicago A | - | - | - |
