1.25" with W&H backpaper consistent with an issue date of 1911. Button pictures with text "Tupper-Macdonald, Reciprocity In Preferential Trade." John Macdonald was Canada's first Prime Minister and Charles Tupper was the sixth. Both men worked to reduce duties on goods exchanged between Canada and the United States. These efforts began as early as 1846 but this button dates from 1911 when there was a major attempt to negotiate reciprocity by the Liberal government of Sir Wilfrid Laurier. The agreement named on this button was to be implemented by concurrent legislation. While the agreement was accepted by the US Congress it was reputed by the Canadians, who ousted the Liberals in the general election of Sept. 21, 1911. Exc. and displays Mint. Only example we've seen.