Letter from Raúl Segura Procelle to John J. Herrera, dated January 12, 1967. Segura Procelle sends Herrera a copy of an interview with Herrera, and asks after the League of United Latin American Citizens.

Postcard sent to John J. Herrera, Mike, and Shep in Houston, Texas from John's son, Douglas M. Herrera in Mexico. Text: "23 Sept 68, Dear Dad, Mike, Shep, San Luis is a pretty pace, muchas bonitas mujeres but I'm itching to get to la Ciudad D. F. So I'm catching the 11:30 A.M. bus out tomorrow so I can register for classes & begin the next day. Having a Corona on you all fellas. Wish me luck, I need it. DMH." The front of the postcard has images of four buildings in San Luis Potosi, identified on the reverse as Teatro de La Paz/La Paz Theatre, Plaza de los Fundadores/The Founders Square, La Caja del Agua/The Water Box, and Palacio de Gubierno/Government Palace.

Letter from Douglas M. Herrera to his father, John J. Herrera dated November 4, 1969. In the letter, Douglas tells his father about upcoming midterm exams, a planned trip to Acapulco, and asks about seeing his family for Christmas.

Letter to John J. Herrera from his son, Douglas M. Herrera, dated November 25, 1969 details a recent trip to Acapulco, Mexico, and his plans for the upcoming Thanksgiving holiday.

Letter from Douglas Herrera to his father, John J. Herrera, dated October 15, 1969. The letter, mailed from University of the Americas in Mexico to Houston, Texas, details the new house Douglas has found near campus. Douglas also wishes his father luck on an upcoming speech and discusses the ways he believes the Latino minority can elevate itself in society through peaceful means and expresses concern over the tactics of the Brown Power Movement.

Letter to John J. Herrera from his son, Douglas M. Herrera, dated May 16, 1969. Douglas details his plans to leave university for summer work in Alaska. The letter is handwritten on loose leaf paper and mailed from the University of the Americas in Mexico to Houston, Texas.

Letter addressed to Mr. and Mrs. John J. Herrera from their son, Douglas M. Herrera, dated January 7, 1969, confirming his safe arrival at the University of the Americas, his new university job, and the house in which plans to live.

Letter to Mr. and Mrs. John J. Herrera from their son, Douglas M. Herrera, dated October 13, 1968. Douglas describes watching the Olympic Games in Mexico, and his plans to move to a different apartment near the Mexican university he is attending. The letter switches from Spanish to English. Douglas explains, “I guess I’ve murdered the family tongue enough for one letter so I’ll revert to a bit of jolly ole English.”

Postcard to John J. Herrera from Terry Serna that reads: "Hi Johnny! Still in the convention mood. Having a ball before returning to the grind! Terry Serna." The front of the postcard has the image of of a waterfall with people in the foreground. The image is identified on the back of the postcard as "Cascada La Cola De Caballo, Horsetail Falls near Monterrey. Monterrey, N. L., Mexico"

Letter to John J. Herrera from a public notary, Mario Garza Ramos, in Matamoros in Mexico, formally giving Herrera authority on behalf of Ana García de Barguiarena and Roberto Barguirena Menchaca with regards to a 1968 Volkswagen car with Mexican registration for their younger son, Roberto Barguiarena García.

Envelope addressed to John J. Herrera, mailed from Guadalajara by Alberto Garibi Harper, Jr.

Letter to John J. Herrrea from Cesar Lazo Hinojosa wishing him a happy New Year. Envelope included with letter.

Letter from Theo C. Adams, American Consul, to Jim Wright, House of Representatives, regarding Francisco Javier Lopez Molinero's case.

Letter from Jim Wright, House of Representatives, 12th District, Texas, to Regulo Rivera, American Consul, American Consulate General, Monterrey, N.L., Mexico with a copy to John J. Herrera, asking help obtaining an immigrant visa for Francisco Javier Lopez Molinero.

Letter from John J. Herrera to Gustavo Díaz Ordaz, President of Mexico, March 27, 1965. Herrera discusses former President JOhn F. Kennedy and current President Lyndon B. Johnson, as well as other Texas politicians.

Letter from John J. Herrera replying to Alberto Garibi Harper, Jr., stating his willingness to work more closely together whenever Herrera has business Guadalajara.

Letter from Alberto Garibi Hernandez, Jr., a young attorney in Guadalajara, to establish an introduction with John J. Herrera.

Letter to John J. Herrera from Arnulfo Gómez García offering his services as an Attorney-at-Mexican-Law for any business Herrera's firm needed to conduct in Mexico.