It can’t be a coincidence – several American and Canadian coins (definitely the quarter, and I think the penny and dime as well) are EXACTLY alike in color, size, weight, shape, and metal. Often you don’t even notice which denomination you have, unless you happen to look at the face. Has this always been so? Who copied who, and why? Did they just figure that the coins would get mixed up anyways, so they may as well make them similar enough not to cause a disturbance?
The idea of the Canadians (God bless their souls) is to make people in the States think they can use Canadian coins in U.S. vending macnines. Of course, it never works, but it gradually, bit by bit, raises the value of the Canadian dolar.
Let’s hear it for Canadian ingenuity!
Probably because they originally were made of specific metals, and the size of the coin was related to the value of that amount of the metal.
Pennies were made of copper. 1¢ worth of copper. Sometimes even called ‘coppers’. The original size of the coin was determined by how much copper the mint could get for 1¢.
Nickels were made of nickel, 5¢ worth of nickel.
Dimes were made of silver. They were smaller than both nickels & pennies because silver was more valuable, and that was as big a coin as you could make with a dime’s worth of silver.
Of course, they are mostly made of combinations of metals today, and the cost of the metal in them has no relation to the face value of the coin any more. But they are kept the traditional size & weight, because that’s what people (and vending machines, and cash registers, etc.) expect.
Don’t have a factual answer, but do have an anecdote about coinage.
Having recently been to DC, after putting my coins back in my pocket from the zip-lock bag (airport security lifesaver), and visiting a Chipotle near my hotel, I was informed by the cashier that my (mistakenly proffered) Canadian quarter was “not money”.
I must therefore surmise that while the coins might look alike in size, it’s easy to tell the difference, and reject the ones you don’t want.
To add to what t-bonham said, The silver dollar was an ounce of silver, the 50 cent piece a half ounce, a quarter, well, a quarter ounce and the dime a tenth. Even though our coins aren’t made of silver anymore, the size (and probably the weight ratios) are still roughly the same. If Canada had the same system, it makes sense that their coins would be the same size and color.
The one cent, 5 cent, 10 cent 25 cent are all the same size/colour. The metal used between the US and CA coins are different. Most US silver coloured coins are nickel/copper. If I recall the CA silver coloured coins are nickel/steel. I think the one cent and 5 cent coins are the same weights but the 10 cent and 25 cent CA coins are lighter then the US counterparts.
The Americans win the weight when it comes to their Ike dollar coin (about 4cm across and something like 22 grams) but Canada wins the beauty contest.
The paper money, while different in look, are the same size.
The Canadians have (and use) their one and two dollar coins. The Americans have 3 different current dollar coins and most people never see them unless they happen to be pulling slots in Las Vegas. In fact, I got a bag of 50 Ike dollars and most people at my work had never seen them before. I left an Ike for a tip at a bar in Vancouver BC and the bartender didn’t realize it was actual money.
Trivia: Canadian coins (except for the penny) are affected by magnets. American coins aren’t. If Seven’s right about the metals used, it’s because of the steel. I’m not sure if it was done that way on purpose or not, but I expect that it’s helpful if one needs a simple way to separate Canadian and American coins.
I just found this on another site (the RCM doesn’t have a great website for facts)
Also from that site…
The American “Nickel” just might have started life as Canadian nickel 
Our money was schizophrenic during most of the 19th century. We used American Eagles and British Sovereigns. It was still famously muddled after we started getting our own currency.
Us colonists were pretty keen on American-style decimal currency, but for some reason the King was pretty bull-headed about us being tied to the pound. Sometime around 1860, after plenty of half-measures and compromises, we finally ended up with a decimal currency that was similar to the American system – except we had 20 cent coins instead of 25 cent coins. (No idea if we called them “fifths” back then – it only stayed that way for a couple of years before we changed over to quarters.)
My dim recall of high school history tells me that the similarity of Canadian and U.S. money has something to do with the Gold Standard and the International Monetary Conference in Paris around that time. (Sorry, that’s lame, but it’s what I got.)
Probably the most useful thing that I can contribute is that Canadian pennies were close to nickel-sized until 1919, when they were shrunk down, specifically to conform to the size of the U.S. penny.
That wasn’t very nice of you. The vast majority of Canadian banks will not accept US coins, except possibly in bulk. The coin would have been worthless to him unless he was planning on visiting the US.
To expand on this, during the years when most countries had their currencies pegged to gold, before 1970 or so, the Canadian and U.S. dollars were very close in value, varying by only a cent or so. Actually in 1960 CDN $1 was worth about USD $1.01
I’m not sure that the dollar was ever intended to be an ounce of silver. During much of the 19th and early 20th centuries an ounce of silver was worth considerably less than a dollar, which was why Western mining and silver interests were so eager to have the government mint their silver into dollars at par (cf. Free Silver movement), and increase the money supply.
Not quite true. American notes are a touch longer and shorter. Usually this is enough that bills designed for American wallets don’t work for carrying Canadian currency.
Canadian coins are, in fact, slightly smaller in diameter than their US versions. That makes it easy for vending machines to separate them.
Until some time in the Sixties, IIRC, the two currencies were pegged at par, and were commonly accepted across the border. Maybe that’s why the coinage was harmonized?
When they were both allowed to float on the international currency exchanges, the US dollar fared better, eventually getting up to about C$1.50, and the Canadian version was no longer freely accepted in the US. Canadian stores even today commonly accept US dollars, but at par or close to it, and keep the difference.
I’ve wondered about this for a long time, and I’ve never heard a satisfactory answer.
I’m very skeptiocal of the “they used the same metals for the coins” suggestion. Even if this were true (I have my doubts), the Canadians could’ve used different metals than the US, or they could’ve used different thicknesses of the same metals, and then the coins would’ve had very different diameters. Furthermore, the Canadian coins follow the same values as US coins, even when the US used to have different valued-coins, which the Canadians either didn’t have, or also gave up as the US did – Half-cents, anyone? Two cent coins? Half Dimes? Canadians have $2 coins, but that’s the sole counterexample I know of. There’s no reason Canadians couldn’t have produced, say, a 20 cent piece, but they don’t seem to have done so.
It seems pretty clear that Canadian coins have been kept the same size (approximately) as US coins as a matter of policy, but I don’ know why that is.
And Canadian nickels have been magnetic (and polygonal)n since before i was born. To my personal knowledge, they’re the only magnetic Canadian coin,
Just for the record there was a third North American dollars-and-cents coinage: Newfoundland, which continued to have its own currency until joining Confederation in 1949. Newfie coins were issued until 1947, and they had 20-cent pieces up until the 1920s.
Growing up 20 miles from the Canadian border, I regularly got Canadian coins in change (at that time, $US and $CDN were very near par) and every so often you would find a Newfoundland penny in the mix.
This is completely wrong. U.S. coins are easily spent in Canada, at all retail outlets no less, and can be exchanged at any Canadian bank without any hassle at all. A U.S. dollar is actually a better tip than a Canadian dollar because it’s worth a little more. I have travelled a bit in Canada, and this is true wherever I’ve been, even in places not close to the border. I spent a whole bunch of U.S. cash at a Canadian Tire in Yellowknife without any hastle at all, and Yellowkinfe is over a thousand miles away from the U.S. border.
This is completely wrong. If you go into any Canadian store (small mom and pop stores excepted, and even there this is true at most of them), they will give you an exchange rate for your U.S. money that is close to what you would get from a bank (it’s not exactly the same, the stores are making money on the transaction, but it’s close enough that usually it’s not worth the extra time and hassle to go to a bank unless there is one right next door.). Saying that all Canadian stores accept U.S. money “At par or close to it” is completely false. Making shit up may be par for the course for you in GD or the Pit, but here in GQ there is a higher standard.
Yes, we gladly accept the mighty greenback. I’ve never been to a store that wouldn’t accept US currency. These days you might only get 10%, as opposed to say 15% at a bank. Of course in a year or so they’ll be at par anyway. 
I can confirm Weirddave’s post. I have had no problem paying for things in Vancouver, BC with US dollars. Like WD, I have purchased tires on the Alcan without any hassles. Most Canadian stores I’ve dealt with don’t mind at all…it gives them a little extra profit if they do, in fact.
This to me seems like the closest we’ve gotten to an actual answer. Could someone (maybe our Coin Dealer/Mod?) verify?
I seriously doubt that, at least in the case of pennies and nickels. It would imply that the mint regularly changed the weight (and, accordingly, diameter and/or thickness) of the coins according to fluctuations in the prices of metals, which it didn’t.
It’s true that the value of money used to be pegged to the value of precious metals - prior to 1933, when possessing gold for monetary purposes was banned in the U.S., this was gold (at the rate of $20.67 per ounce), and until 1873 gold and silver were used parallelly under a system referred to as bimetallism, with a determined relation between the values of the two metals (16 to 1 in the case of the U.S. dollar). But this never extended to other metals than gold and silver.