| Name | Participants | Dates | Stamps | ||
| 100th Anniversary of Ingrid Bergman | 2 | (with Sweden) | 2015 | 4 | |
| 4th Anniversary of the R..ds Compacts of Free Asso | 3 | (with Marshall Islands - Micronesia) | 1990 | 6 | |
| Apollo-Soyuz | 2 | (with Russia) | 1975 | 7 | |
| Australia 200th - Australia-United States | 2 | (with Australia) | 1988 | 2 | |
| Champlain surveys the East Coast | 2 | (with Canada) | 2006 | 2 | |
| Children's Book Animals | 2 | (with Great Britain) | 2006 | 16 | |
| Cinco de Mayo | 2 | (with Mexico) | 1998 | 2 | |
| Columbus discovery 500th | 4 | (with Italy - Spain) | 1992 | 45 | (incomplete) |
| cranes | 2 | (with China, PRC) | 1994 | 4 | |
| Florida settlement 400th | 2 | (with Spain) | 1965 | 2 | |
| French Revolution 200th | 1 | 1989 | 1 | (incomplete) | |
| Germany-US immigration 300th | 2 | (with Germany) | 1983 | 2 | |
| Grace Kelly | 2 | (with Monaco) | 1993 | 2 | |
| Greta Garbo 100th | 2 | (with Sweden) | 2005 | 3 | |
| Hanukkah 1996 | 2 | (with Israel) | 1996 | 2 | |
| History of Hockey | 2 | (with Canada) | 2017 | 6 | |
| Irish immigration | 2 | (with Ireland) | 1999 | 2 | |
| James Hoban death 150th | 2 | (with Ireland) | 1981 | 3 | |
| John McCormack 100th | 2 | (with Ireland) | 1984 | 2 | |
| Mexican independence 150th | 2 | (with Mexico) | 1960 | 7 | |
| New Sweden 350th | 3 | (with Finland - Sweden) | 1988 | 8 | (incomplete) |
| Nobel Prize 100th | 2 | (with Sweden) | 2001 | 5 | (incomplete) |
| Peace Bridge 50th | 2 | (with Canada) | 1977 | 2 | |
| Philip Mazzei 250th | 1 | 1980 | 1 | (incomplete) | |
| Piaf & Davis | 2 | (with France) | 2012 | 4 | |
| Republic of Palau | 2 | (with Palau) | 1995 | 6 | |
| Sea Creatures | 2 | (with Russia) | 1990 | 8 | |
| Space Accomplishments | 2 | (with Russia) | 1992 | 8 | |
| St Lawrence Seaway 25th | 2 | (with Canada) | 1984 | 2 | |
| St. Lawrence Seaway | 2 | (with Canada) | 1959 | 2 | |
| Statue of Liberty 100th | 2 | (with France) | 1986 | 2 | |
| Stockholmia 86 | 2 | (with Sweden) | 1986 | 8 | |
| Switzerland 700th | 2 | (with Switzerland) | 1991 | 6 | |
| Tenth Death Anniversary of William Saroyan | 2 | (with Russia) | 1991 | 2 | |
| Treaty of Paris 200th | 2 | (with France) | 1983 | 2 | (incomplete) |
| US-Morocco relations 200th | 2 | (with Morocco) | 1987 | 2 | |
| US-Netherlands relations 200th | 2 | (with Netherlands) | 1982 | 3 | |
| US-Sweden treaty 200th | 2 | (with Sweden) | 1983 | 2 | |
| USA 200th | 2 | (with Canada) | 1976 | 2 | |
| voyages of Columbus | 2 | (with Italy) | 1992 | 8 |