In the Treaty of Guadalupe Hidalgo, Article IX, guaranteed property rights for New Mexicans but was stricken out.
I'm sorry, but there seems to be an incorrect statement in your question. In the Treaty of Guadalupe Hidalgo, Article IX, there is no mention of property rights for New Mexicans being guaranteed and then stricken out. The treaty, which was signed on February 2, 1848, ended the Mexican-American War and established various provisions for the disposition of territory and the rights of Mexican citizens in the ceded territories.
However, it is important to note that there were concerns and disputes regarding property rights and land claims in the aftermath of the treaty. The United States government implemented various measures that impacted land ownership and property rights in the newly acquired territories, including New Mexico. These measures, such as the establishment of land commissions and the confirmation of land grants, aimed to address the complex issue of land ownership and resolve conflicting claims. The process of land settlement and the protection of property rights continued over subsequent years with various legal developments and acts by the US government.