Today a bit of Canadian history from the button box.
This is a uniform button from the Canadian Militia. You can think of this organization as being a combination of National Guard and Army reserve. The lineage of the militia goes all the way back to the days of French rule in Canada. A summary of militia history can be found HERE.
I'd call this an effective design. It's not easy to make a chubby rodent look capable of combat but I think they pulled it off. Various militia buttons feature either a beaver or the crown as the central device. I've seen one source that plausibly says the crown was favored in English speaking Canada, the beaver in the French speaking parts. As to the date.....I thought 1900 give or take a decade. When war broke out in 1914 it was realized that the militia was not much of a fighting force and it seems to have become largely obsolete at that time.
The back of the button makes things more interesting.
P. Tait and Co. Limerick (Ireland). Peter Tait started a factory for making uniforms in 1852. Two years later the Crimean War proved good for business. Soon after that the American Civil War broke out and Tait not only sold uniforms to the Confederacy but even delivered them on his own small fleet of ships.
Tait prospered, being elected Mayor of Limerick and later being knighted. He handed the business over to his son in the mid 1870's. At this point it was renamed "The Auxiliary Forces Clothing and Equipment Company".
I suppose the buttons used could have retained the earlier company name, but it does appear my ball park dating of the item could have been off by a couple of decades.