Bulosan's America Is in the Heart is one of the few books that detail the migrant workers' struggles in the United States during the 1930s through the 1940s, a time when signs like "Dogs and Filipinos not allowed" were common. The struggles included "beatings, threats, and ill health". In this book, Bulosan also narrated his attempts to establish a labor union. Bulosan's book had been compared to The Grapes of Wrath except that the main and real characters were brown-skinned. Despite the bitterness however, Bulosan revealed at the final pages of the book that because he loved America no one could ever destroy his faith in his new country. In this personal literature, Bulosan argued that despite of the suffering and abuses he experienced America was an unfinished “ideal in which everyone must invest (…) time and energy, (…) this outlook leaves us with a feeling of hope for the future instead of bitter defeat.” According to Carlos P. Romulo when he was interviewed by The New York Times, Bulosan wrote America Is in the Heart with “bitterness” in his heart and blood yet with the purpose of contributing “something toward the final fulfillment of America”.
Through America Is in the Heart, Bulosan was able to share a unique perspective on Asian life in the United States in general, but particularly that of Filipino-Americans during the first half of the 20th century. It is a book that encourages people of all races and genders to ponder and improve their relationships with one another.