Walt Witman is an American romanticist, and he is very practical. It is not surprising that he should write about work. Since, I am also a romantic, I can relate and know much of why he wrote what he did.
America was founded in 1776 as an establish nation. People could not work freely without a socialist dictator in England, which were the kings or queens that dominate and still to some degree dominate England. We were the first country to establish a system based on capitalism and the freedom to do as we wish. We may work without the direct interference or was once able to, and say whatever we wish. Naturally America was the ideal land of opportunities and people immigrated from other countries to get a better envioronment and a better education, work, and general life. Naturally, since America was a land of opportunity and liberty jobs were numerous, and this country serves as the best place to work and be happy in. Many people come here to work and earn a living. They are certainly more well off.
Witman naturally a romantic and a person who idealize the work writes about work and an ideal society that exchange products at their own will. The happiness of it all and how it should be.