Hi Kellie-- actually, the U.S. is not particularly under-represented eclipse-wise, it just seems that way lately. The problem is that the eclipse path is so small relative to the Earth's size, that the probable frequency for a total solar eclipse to occur at any one spot on Earth is, on average, once every 375 years. There are some geographical effects-- the main one being that total eclipses are more likely in the northern hemisphere than the southern hemisphere (because summer in the northern hemisphere happens when the earth is a bit further from the sun, and so the solar disk is a bit smaller, making it easier for an eclipse to be total rather than partial). But the U.S. is not any less likely to see an eclipse than say, Europe or Asia.
As for temperature drop-- I found one reference in which measurements found generally a few degrees celsius drop, with the biggest being 6 degrees celslus. But I am not sure if this is the biggest ever!
cheers,
Sarah