Which of the following was part of the Treaty of Guadalupe-Hidalgo?

The Treaty of Guadalupe-Hidalgo, signed in 1848, ended the Mexican-American War and resulted in significant territorial changes. One of the key provisions of the treaty was the guarantee of property rights for Mexicans who resided in the newly acquired territories. This assurance was crucial as it intended to protect the land and property of Mexican citizens, ensuring that they would not be dispossessed of their property due to the change in governance.

Options regarding the construction of railroads and the creation of new state boundaries were not explicitly stipulated in the treaty itself. While railroad development would later be influenced by the new territories, it was not a direct provision of the treaty. Similarly, while the treaty did indeed create new boundaries, it did so as a consequence of the land cessions laid out in the treaty rather than as an outlined term. The notion that all Mexican inhabitants had to leave was contrary to the treaty's intentions of protecting those residents' rights and ultimately was not enforced.

Thus, the correct option highlights the treaty's aim to safeguard property rights, which was a crucial aspect of its negotiation and purpose during that historical period.