For example, I just searched Shakespeare and saw hundreds of references to "thousand", a dozen or two references to "million", and no occurrences of the word "billion".
Update: The Wikipedia article on the long and short scales was useful.
Although I haven't read it, you may be interested in the book, Everything and More: A Compact History of Infinity by David Foster Wallace. I believe this book discusses anthropological studies showing that in most hunter-gather societies three is effectively the highest number (anything higher than four is refered to with a concept of "many").
According to Wikipedia, by the 5th century BCE the Vedic civilization gave names to many very large numbers including multiple infininties. The largest number the Ancient Greeks had a word for was only one hundred million, but Archimides worked with numbers up to 10^64.
According to the Online Etymology Dictionary, the concept of "a billion" made its way from French into English by about Shakespeare's time.