Career
After the war ended, he played a part in the development of Colorado and in particular the city of Denver. Jacob Downing was born in Albany, New York in April 1830, the youngest of 11 children of Jacob Downing, Senior (1785-1858) and Jane (née Winne) Downing.
Downing, Senior was, according to one source the owner of several farms and a successful entrepreneur.
The younger Downing was schooled at the Albany Academy. At 14, he went to work as a clerk at the Albany City Bank.
In 1850, he was badly injured aboard the steamer Alabama when the boiler burst. He studied law in Chicago and was admitted to the Illinois bar in 1858.