a Vermont educator and military officer. He is prominent for developing and implementing a system for receiving and training troops for the Union Army during the American Civil War. Jackman wrote several articles and treatises on mathematics and other topics. In the 1840s he prepared an article on constructing an underwater telegraph, including methods of in...

a Vermont educator and military officer. He is prominent for developing and implementing a system for receiving and training troops for the Union Army during the American Civil War. Jackman wrote several articles and treatises on mathematics and other topics. In the 1840s he prepared an article on constructing an underwater telegraph, including methods of insulating and laying cable. When the Transatlantic line was laid in the 1850s and 1860s Jackman received credit for originating the idea.