Foreigners owned a lot of land in Mexico:

During the Díaz regime thirty-nine million hectares of untitled land was converted into private property, or about a fifth of Mexico’s total land area, equivalent in size to the state of California. Much of it was highly concentrated in terms of ownership, and some also went to foreign interests: 547,000 hectares in northern Mexico, for example, became the sole possession of the Richardson Construction Company in Los Angeles. The newspaper tycoon William Randolph Hearst also acquired a large estate for himself in the state of Chihuahua, one measuring 350,000 hectares, that is, a property of 1,351 square miles, or more than four times the size of New York City’s five boroughs. Americans held 130 million acres total, much of it highly valuable space on or near the coasts and along the border. In addition to Hearst's 7 million acres, Texaco owned 4.7 million acres, Texas businessman Edwin Jessup Marshall 5.5 million (including the 2.5-million-acre Las Palomas hacienda, the largest fenced property in North America), 4.7 million by Texaco, and 3.8 million by the Continental Rubber Company. Much of this land had once belonged to peasants whose communities lacked the power to effectively contest the Diaz goverment's policies. "I really don't see what is to prevent us [Americans] from owning all of Mexico and running it to suit ourselves," Hearst said.

The long-term fate of Babicora, Hearst's million-acre ranch: in 1908, fifty campesinos ride there, protesting the ranch's incursions on communal land. Hearst's men realign their fences. During the Revolution, Pancho Villa attacks the ranch, takes 60,000 head of cattle and kills a worker. Hearst uses his paper, the San Francisco Examiner, to demand that the government protect his property from the "murders and outrages already committed upon our citizens and soldiers." In 1921, he flies to Mexico City to meet President Obregón, who agrees to protect his land. Later in the decade, Calles confiscates part of the land and returns it to peasants. In 1935, the Cardenas government takes 175,000 acres, and 117,000 more in 1940. It is fully nationalized in 1954, after Hearst's death, the Mexican government paying "a bargain price of" $2M for the last 50,000 hectares (about 123,500 acres).

US Secretary of State Frank Kellogg, 1925:

It should be made clear that this Government will continue to support the Government in Mexico only so long as it protects American lives and American rights and complies with its international obligations. The Government of Mexico is now on trial before the world. We have the greatest interest in the stability, prosperity, and independence of Mexico....But we cannot countenance violation of her obligations and failure to protect American citizens.

A Mexican oil bond, 1912:

In response, Calles has legislature enact a new law wherein all oil companies must apply to Mexican government for confirmation of their concessions. If it had performed a "positive act" (ie had done something with the land to get oil out of it, or to start to get oil out of it), before May 1, 1917, then the company would retain the land for 50 more years. After some diplomatic maneuvering, the US lets Mexico deal with the question, which it does by ruling that the new permits would have to be applied for, but would not expire after 50 years.