We, the USA citizens,
, are the proud user of the US Customary Measurement System except that nowadays we are just about the only place that does use it. The Bahamas and Liberia and the USA use inches and quarts etc, everyone else seems to like the Metric System. It just seems to Americans that it is easier to add 1 3/4 plus 2 5/16 plus 1 instead of the extremely awkward 110mm + 155mm + 35.
When you throw in, or out, as the case may be, the British Imperial System of dry/wet measurement, there's been some spillage or slippage over the years, with the US pint slightly larger that the Brit pint (take that!!) with the US gallon being 2/10th more than the Imperial gallon. (Though 2/10ths of a what, I don't know.) I also don't know when this imbalance occurred (the revolution?) maybe Setanta has a reference, I do know that many pages of oil production contracts between US and foreign companies are concerned with how big a barrel is a barrel. (which by the way is the only measurement not listed in my big list of measurements page.....
)
But to get to Primaries, this is much
simpler
Try here for actual information.
http://www.ctv.ca/generic/WebSpecials/us_primaries/index_primer.html
There are forty-something primaries in the various States. It's just that some are perceived as more important than others, more of an indicator of what the pulse of voters is. This is a somewhat media inspired idea because it does give them a kind of horse race that they have the intellectual ability and technology to cover.