Final answer:
The Mexican working class faced loss of land, cultural alienation, and economic struggles after the Treaty of Guadalupe Hidalgo due to discriminatory actions and broken treaty promises by the U.S.
Step-by-step explanation:
After the signing of the Treaty of Guadalupe Hidalgo in 1848, the Mexican working class, particularly in the new American Southwest, faced significant hardships. Many Mexican and Mexican-Americans lost their lands as the United States, Texas, and California governments declared Mexican and Spanish land deeds 'imperfect' and questioned their authenticity.
This resulted in a massive transfer of property from the original landowners—tejanos and californios—to white settlers. Consequently, former landowners became laborers, often on the very lands they once owned, and faced systematic discrimination including legislations such as California's Greaser Act. The treaty had promised protections for property and rights for the Hispanics in the ceded territories, but these were often ignored, and within a generation, the Mexican working class struggled with second-class citizenship status, cultural alienation, and significant reductions in land ownership and economic status.