Multiple choice general knowledge science & technology In which decade was the telegraph invented? 1810s 1840s 1870s 1890s Reveal answer Fill a bubble to check yourself B Correct answer Explanation The electric telegraph was developed and patented in the 1830s-1840s, with Samuel Morse's famous 1844 demonstration from Washington to Baltimore being the pivotal moment. The 1810s were too early, and the 1870s-1890s were too late.