Over the years, Americans have licked at least four stamps issued to pay tribute to people with roots in Canada, says the United States Postal Service.

The Oregon Territory three-cent stamp issued in 1948 commemorates John McLoughlin, a native of Riviere-du-Loup, Que. and Jason Lee, born in Stanstead, Que., which at the time was considered a part of Vermont. The stamp features a covered wagon pulled by a team of horses or mules flanked on the left by a headshot of McLoughlin and on the right by Lee. The words Oregon Territory Centennial are under the wagon, says U.S. post office spokesman Barry Ziehl.

McLoughlin was an explorer and fur trader, and later a physician, who joined the North West Fur Co., which later merged with the Hudson's Bay Co. In 1824, he was made director of the Hudson's Bay Co., and established a headquarters at Fort Vancouver, now Vancouver, Washington, where he organized new trading posts, kept peace among the Indians and won control of the fur trade on the Pacific coast. Recognizing Oregon's potential, he encouraged settlement of the region by French-Canadian farmers. Eventually he resigned from the Hudson's Bay Company and became an American citizen.

Lee was a Methodist clergyman who was recognized as a pioneering missionary in the Pacific Northwest. He set up the Oregon Mission to establish schools and agriculture near Salem, Oregon and also formed the Oregon Institute, now Willamette University. He later returned to Stanstead, Que. where he died in 1845.

Four-cent stamps released in 1959 in the Silver Centennial issue commemorate the 100-year anniversary of the discovery of silver at Mount Davidson in the Virginia Range, in Nevada. The Canadian involved was Henry T.P. Comstock, who was born in Trenton, Ont., and in 1859 claimed ownership of a vein rich in gold and silver. The find led to the establishment of Virginia City, which is now a ghost town. The lode yielded more than $300 million in gold and silver in the first 20 years and was abandoned in 1898.

The stamp depicts three prospectors near a trough, including Comstock, who laid claim to the land after leaving Canada and working in the fur trade in New Mexico. Comstock, who was nicknamed "old pancake" and is described in one American history book as "a Canadian blowhard," sold his share in the find for $11,000 and later lost his money in a bad investment. Eleven years after striking it rich, he died, either by suicide or at the hands of robbers.

The six-cent Father Marquette stamp was issued in 1968 in honour of Louis Jolliet (spelled Joliet on the U.S. stamp), a French Canadian explorer and Jesuit priest born in Beaupr‚, near Quebec City. The stamp features a canoe with four people in it, one, believed to be Jolliet. He and Marquette sailed the Mississippi River, in mid-July 1673 reaching the mouth of the Arkansas River, far enough south to prove it flowed into the Gulf of Mexico, rather than the Pacific Ocean. Jolliet later explored Labrador and Hudson Bay and was appointed royal hydrographer of New France in 1697.

Vilhjalmur Stefansson, a native of Arnes, Manitoba, appears on the 22-cent Arctic Explorer stamp released in 1986. The stamp features the controversial explorer's photograph, an Arctic scene and a map of the Arctic. The son of Icelanders, he moved with his family to the Dakotas in 1880 and explored the Arctic between 1906 and 1918, covering more than 32,000-square kilometres of the frigid territory. His message was that the Arctic was not bleak and frozen wasteland but a habitable region that must be developed.

Stefansson discovered some of the world's last major land masses, including Lougheed, Borden, Meighen and Brock islands but was dogged by controversy, after making enemies during the Canadian Arctic expedition between 1913 and 1918, and because some of his projects went bust. One such failure was his plan to domesticate reindeer in northern Canada. After the mid-1920s most of his time was spent in the United States where he was regarded as one of the world's foremost arctic experts. He died in Hanover, New Hampshire.

Michael Schreiber, spokesman for Linn's Stamp News, an influential publication based in Sidney, Ohio., says the four stamps are "common commemoratives" valued today at between 25 cents to 50 cents each.