In Whitman's " I hear America singing" what binds the workers together

In Whitman's I Hear America Singing, the workers share the same vision about their rights and their wish to find joy in their works. They all have the same objective, to make a strong, united and prosperous country, by sharing joy because of their productivity and their labor.

i think the answer would mist likely be an adjective clause, because unhappy is an adjective.