For all Canadians – and Americans – who care about the natural environment on the continent we share, today is indeed a very special anniversary. It was during a March 13-14, 1991 visit to Ottawa by President George H.W. Bush  that he and Prime Minister Brian Mulroney signed the Canada-United States Air Quality Agreement (known by most as the Acid Rain Treaty).Negotiating this treaty with the Americans had been a worthy goal Mr. Mulroney had pursued ever since he became PC leader in 1983. It was a great day for him and his government and, more importantly, a great day for future generations of Canadians as the treaty helped along the road to ending acid rain’s scourge.No less an authority than former Green Party leader Elizabeth May confirms this view. “Brian Mulroney did not let the ball drop on the importance of fighting acid rain,” she said in an interview with CBC years later.  In later comments to the Ottawa Citizen, she added: “Mulroney placed acid rain as his top bilateral issue when dealing with the U.S. He insisted on real action at home, with agreements with the seven eastern provinces to cut acid rain-causing emissions by 50 per cent."Ultimately, the U.S. agreed to the same binding target … Someone clever once said: ‘To leave a legacy, you have to know one big thing and stick with it.’Fortunately for Canadians, Mr. Mulroney was determined to leave a legacy and he stuck with it. He decided acid rain was a problem, and he cleverly combined charm with resolution and got former President Bush Sr. to sign a treaty reducing acid rain-causing emissions by 50 per cent.”And in looking back 30 years, one also has to give credit to the late President Bush. He faced great opposition within his own Administration but held firm and supported this treaty to the benefit of both Canadians and Americans.caption id="attachment_543759" align="aligncenter" width="440" President Bush and Prime Minister Mulroney at the signing of the Acid Rain Treaty/captionArthur Milnes is an accomplished public historian and award-winning journalist.  He was research assistant on The Rt. Hon. Brian Mulroney’s best-selling Memoirs and also served as a speechwriter to then-Prime Minister Stephen Harper and as a Fellow of the Queen’s Centre for the Study of Democracy under the leadership of Tom Axworthy.  A resident of Kingston, Ontario, Milnes serves as the in-house historian at the 175 year-old Frontenac Club Hotel.