The largest professional occupation for men in the united states by 1860 was

engineering

Explanation:  This was the time of the industrial revolution and engineering and working in the manufacturing business became a predominant profession for men. People started moving into towns and jobs in agriculture started going down while engineering grew.

mount st. helens in washington erupts, causing a massive avalanche and killing 57 people on this day in 1980. ash from the volcanic eruption fell as far away as minnesota. seismic activity at mount st. helens, which is 96 miles south of seattle, began on march 16.