1845
ID: 853
Telegraph lines spread rapidly across America and Europe
ID: 853
1845
ID: 854
Gustav Kirchhoff develops mathematical laws for electrical circuits - systematic engineering design
ID: 854
1845
ID: 855
Christian Friedrich Schonbein discovers gun cotton (nitrocellulose) - first synthetic polymer
ID: 855
1845
ID: 5786
March 1845
Johnny Appleseed dies in Fort Wayne - planted estimated 100,000 square miles of apple trees across frontier
ID: 5786
1845
ID: 5680
September 1845
Irish Potato Famine begins - Phytophthora infestans destroys crops, one million die, two million emigrate
ID: 5680