This theme is a little more subtle, but with all of this American dream stuff, you can see that class and money matter in Long Day's Journey Into Night. The dad has done well financially, and he finds Socialism distasteful. As James points out, he learned the value of a dollar the hard way as a child, and his greatest fear is role people taking advantage of his wealth and cheating him. As a result, he has a hard time spending money, even on worthwhile causes, like quality healthcare for the family.
The family has two full-time helpers, and the mother's attitude toward them is telling. She thinks one is positively subhuman, but she's willing to use the other as a surrogate friend when she gets really lonely. The relationship isn't really one of friendship from the mother's end though – she's more looking for anyone who'll listen.
Through their frequent dehumanization, Cathleen and Bridget reveal the Tyrones' failure to separate themselves meaningfully from the wealthy families with whom they don't want to associate (such as the Chatfields and Harker).