The first piano was invented in Florence, Italy in 1700 by Bartolomeo Cristofori (1655 – 1732), a craftsman who repaired harpsichords for Italy’s royal court. Cristofori’s invention was a simple keyboard that he called a gravecembalo col piano et forte, “keyboard instrument with soft and loud,” named for the strings that produced different dynamic levels upon vibrating when struck by small wooden hammers covered with deerskin. Cristofori experimented with the instrument’s design throughout the years, and the instrument grew popularity among the upper class. By 1730 pianos were purchased and played by the most elite Europeans.

Although still expensive, pianos were made smaller by the 1760s so that wealthy families could own them in their homes. Wolfgang Amadeus Mozart (1756 – 1791), a pianist prodigy, was born into such a home. He began touring Europe at four years old, giving concerts alongside his musically talented family.

By 1770, the piano had reached America by German
immigrant John Behrent, a piano maker. Most American songs composed then related to the American Revolution, involving dynamic melodies to describe the war.

Source:

http://iml.jou.ufl.edu/projects/Fall05/pfaff/history.html