The invention that revolutionized communication across long distances in the 19th century was the telegraph. Developed in the 1830s and 1840s, the telegraph allowed for the instantaneous transmission of messages over wires using electrical signals. Samuel Morse, one of the key figures behind its development, also created the Morse code, a system of dots and dashes to represent letters and numbers. The telegraph dramatically transformed both personal and commercial communication, facilitating quicker news dissemination, business transactions, and coordination of transportation and logistics. It laid the groundwork for further advancements in communication technologies, shaping how information is exchanged globally.