Singer tells that the trade has gone; if you go to a shop without money, you can't buy. If you ask for a job, there is none; tradesmen walk the street looking for work; soldiers and sailors have come home to starve. He hopes the hard times will not last.
Kennedy seems to think that this song arose in the recession following a war, since sailors and soldiers were returning home to find no work. But the British military did not institute a true draft until World War I; the size of the military stayed relatively constant. And economic trouble was constant in the late eighteenth and early nineteenth century; the population was growing faster than the system could expand. So this could be just a song of falling standards of living. - RBW