| 1990 | Florex (Orlando) | Christine Jolly | "Postal Markings of Ireland to the Reforms of 1857" |
| 1991 | Omaha Stamp Show | Mark Sawyer | "Germania Issues of 1900-1922" |
| 1992 | World Columbian (Chicago) | Kathryn Yadon | "The Bank Note Issues of 1870-1890" |
| 1993 | Sescal (Los Angeles) | Andrew Kelley | "2c Red Washington Head, 1922" |
| 1994 | Philadelphia National Stamp Show | Charlotte Verge | "The Owls" |
| 1995 | Chicagopex | Charles Vukotich | "U.S. Bulk Letters: False Frankings 2/3/91-12/31/94" |
| 1996 | Indypex (Indianapolis) | Joyce Adams | "The Quetzal Bird in Guatemalan Philately" |
| 1997 | Indypex | Ellice Miller | "How Writers Use Flowers to Interpret Their Ideas" |
| 1998 | Greater Toronto Stamp Show | Tim Jones | "The History of Man's Flight in the Earth's Atmosphere" |
| 1999 | Peach State Stamp Show (Atlanta) | Devin Shane Luster | "Basketball" |
| 2000 | Indypex | John Ryle | "Indiana 4-Bars - Types and Usages" |
| 2001 | National Topical Stamp Show | Dzintars Grinfelds | "The 'Three-Star' Coat of Arms Issue of Latvia, 1922-1933" |
| 2002 | National Topical Stamp Show | Kent Kuran | "Postal History of California to 1900"
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| 2003 | NAPEX (McLean, Va) | Dzintars Grinfelds | "The 'Three-Star' Coat of Arms Issue of Latvia, 1922-1933" |
| 2004 | Indypex | Amber Reilly | "In Come the Pigs" |
| 2005 | ROPEX (Rochester, NY) | Dzintars Grinfelds | "Central Lithuania" |
| 2006 | Indypex | Kurt Glatzfelder | "The Vostok Program" |
| 2007 | National Topical Stamp Show | Alyssah Xenia C. Alcala | "Her Majesty Queen Elizabeth II" |
| 2008 | Indypex | Dzintars Grinfelds | "The 'Three-Star' Issues of Latvia, 1921-1923" |