In 1497 Spain introduced a silver Peso (Real de a ocho) worth 8 reales. This coin was very common in Europe and colonial America until the early 1800s. These 'pieces of eight' were one of the most common coins of their time.
The title references the original gold dollars, which were minted so as to be easily clipped into eight smaller pieces. The modern term "two-bit", speaking of two of these eight and thus a quarter of a dollar, derives likewise.