I overstayed the stamp on my Canadian passport in the USA by a year,?
Only when you attempt to return to the USA. Canada wont care and have to admit you as you are a Canadian citizen. You have more than 180 days of unlawful overstay. That is an automatic three year bar from entry into the USA. So the next time you seek to enter the USA expect to be denied entry for this reason. Remember that the USA and Canada share border crossing information so the fact you reentered Canada on a given date long after your visitor visa expired will likely be discovered. You wont be detained or questioned in Canada. But expect a difficult to impossible ability to cross into the USA for years afterwards. And if you are attempting to enter the USA and questioning would lead to you needing to disclose your overstay and you fail to do so, you can receive a lifetime ban from entry into the USA.