When the Costa Rican government defaulted on…

When the Costa Rican government defaulted on its payments in 1882, Keith had had to borrow £1.2 million from London banks and from private investors in order to continue the difficult engineering project.

In exchange for this and for renegotiating the interest on Costa Rica's own debt, from seven percent to two-and-a-half percent, the administration of President Próspero Fernández Oreamuno agrees to give Keith eight hundred thousand acres (thirty-two hundred square kilometers) of tax-free land along the railroad, plus a nnety-nine-year lease on the operation of the train route.

These terms are made official in a document signed by Keith and cabinet minister Bernardo Soto Alfaro on April 21, 1884 (known to Costa Rican historians as the "Soto-Keith contract").

He is de facto the land owner of at least five percent of the total territory of Costa Rica.

The two most powerful cabinet ministers in the government of President Fernández are his son-in-law Soto (who will succeed him after his death) and his brother-in-law José María Castro Madriz, who had previously served twice as President of Costa Rica.

In 1883, Minor Keith had married Cristina Castro Fernández, who is the daughter of Castro, niece of President Fernández, and cousin-in-law of Soto.