“Machaca” is Mexican dried meat or “beef jerky.”  “Machacado con heuvo” is when the dish is served with eggs. The names are Mexican, but the dishes are popular in Texas along the border, especially in Brownsville.
 
 
(Oxford English Dictionary)
machaca, n.
[< Mexican Spanish machaca (cf. Castilian Spanish use in sense ‘pounder, crusher’) < Spanish machacar to pound, to crush (1605; earlier as machucar (1251)), perh. orig. a Mozarabic form ult. < the same base as French

massue (see MASUEL n.); cf. Spanish macho large hammer for forging iron (1490), perh. a Mozarabic variant of mazo (1220-50), a masculine form of maza mallet (see MACE n.2).

The past participle of machacar is used in carne machacada and also to form a noun machacado; both of these occur earlier in English contexts in the same sense as machaca:
1944 E. ZELAYETA Elena’s Famous Mexican & Sp. Recipes 48 Carne Machacada Con Hongos. Pounded Beefsteak with Mushrooms. 1952 M. RYWELL Mexican Cook Bk. 22 Eggs with meat (Machacado con Huevo). 1952 M. RYWELL Mexican Cook Bk. 31 Machacado… Pound and shred beef. Fry beef in hot fat and add onion, salt, pepper, chili powder, garlic, spices, vinegar [etc.].] 

A Mexican dish consisting of strips of dried meat (esp. beef) shredded, pounded to a pulp, and fried with onions, egg, tomatoes, peppers, etc. Also fig.
1972 Los Angeles Times 28 May (Calendar Suppl.) 55/2 A Mexican tardeada is a Sunday fiesta… There are special dishes, such as menudo, machaca, chorizo, carnitas. 
       
Wikipedia: Machaca
Machaca or machacado is a Mexican dish of shredded beef (often dried), and sometimes cooked with eggs, onions and chile peppers (with some regional and economic variations). It is also served in as a taquito, burrito, torta, or a plate with beans and rice. The name Machaca is used in the Southern part of Mexico and in the northwestern state of Sonora, and ‘Machacado’ in the North where it originated. 

Wikipedia: Machacado con huevo
Machacado con huevo is a dish which consists of shredded dry beef that is scrambled with eggs. Its name means “shredded with eggs” in Spanish. The shredded dry beef, carne seca, is said to have originated in the town of Ciénega de Flores, about an hour north of Monterrey, Mexico. The early settlers in the area air-cured beef so that it would be preserved. This particular dish was made famous by Tía Lencha, a local woman who prepared it and eventually sold it in a restaurant. Today there is a commercially available Tia Lencha dried beef in most supermarkets in Mexico.

The basic machacado con huevo is made with eggs and dried beef. Chopped tomatoes, onions and jalapeños or serrano chile peppers can be added, or salsa can be cooked into it, to create another version.

Machacado con huevo often comes as a “taco” presentation. A typical recipe goes like this:

1 tablespoon butter or margarine
6 large eggs, lightly beaten
2 cups shredded beef filling
10 (8-inch) soft taco-size flour tortillas, warmed
1 (16-ounce) can refried beans, warmed
2 cups (8-ounces) shredded cheddar or fancy shredded Monterey Jack cheese  
 
Cooking…South of the Rio Grande
by George Luther Nelson
San Antonio, TX: The Nolan Printing Company
1935
Pg. 20:
Machacado
1 lb. dried beef
1 small onion finely minced
1 clove garlic mashed
1/2 teaspoon ground spices
1 tablespoon Chile powder
Dash of black pepper
1/2 teaspoon salt
1 teaspoon vinegar
4 tablespoons canned tomatoes
6 tablespoons fat
 
Pound the beef well and shred. in hot fat fry beef, onion, garlic, spices and vinegar. When meat is brown and onion is tender add well mashed tomatoes. Cook until almost all of the tomato juice has been cooked away. Break in 3 eggs, stir gently and serve while hot.
 
Delicious with hot Tortillas.
 
10 December 1959, Los Angeles Times, pg. D13:
Machaca Adds Touch
of Mexico to Dinner
MONROVIA—A Mexican main dish known as “Machaca” is the favorite recipe of Mrs. John Harvey, 521 Cloverleaf Dr. It is one of many recipes she has received from friends during visits to Mexico.

The tangy dish features round steak with green chile sauce. The recipe, as given below, serves eight persons.
MACHACA
1 1/2 lb. top round steak (1/2-in. thick)
2 small cans green chiles cut in strips
1 cups canned tomatoes (or fresh, peeled)
2 cloves garlic
1 large onion, sliced
1/2 cup flour
1 teaspoon salt
1/8 teaspoon pepper
1/4 teaspoon cumino
1/3 cup oil
1/2 cup water (or 1 cup if fresh tomatoes are used)
 
Combine flour, salt and pepper in paper bag. Put julienne strips of steak in bag and shake well until all strips are covered. Heat oil in heavy skillet or Dutch oven and add meat and garlic. Brown meat well. Discard garlic and add sliced onion, cook a few more minutes. Add tomatoes, chile, comino and water.
 
Cover and cook an hour to an hour and a half, or until meat is tender. Add small amounts of water, if necessary. (This meat is improved if made the day before serving and stored in refrigerator over night). Heat in casserole in oven before serving.
 
Machaca is best served with flour tortillas which may be purchased at the grocery store. Heat tortillas on a grill or oven open burner. They may be filled with Machaca and rolled, or used as a spoon in traditional Mexican manner.
Refried beans, Spanish rice and a tossed green salad complete the menu.
 
17 June 1960, Modesto (CA) Bee, pg. A5 ad:
Burrito Machaca and Tostada…75c
(...)
TAMPICO CAFE
704 7th St.
 
3 August 1969, Dallas Morning News, section E, pg. 7:
HE HAS INVENTED a couple dishes on the menu: Machacado con Huevos, an omelette folded with lean taco meat and seasoned with chili con queso; and enchiladas Suisse (Swiss) has sour cream, no less.
 
11 June 1972, Dallas Morning News, “An Exotic Manse Seen In Brownsville” by Frank X. Tolbert, section A, pg. 39:
ANOTHER restaurant on my recommended list is Alfredo Lavios’ institution on Boca Chica boulevard in Brownsville. When I was there the other day, I sampled the machacado con huevos y frijoles, this being an omelette with beef jerky among the ingredients and served with refried beans.
   
29 August 1972, Dallas Morning News, “About Restaurants on Tex-Mex Border” by Frank X. Tolbert, section A, pg. 17:
The omelet is not to be confused with huevos rancheros (eggs ranch style) or machacado (eggs scrambled with bits of dried beef or jerked beef).
 
20 July 1973, Fresno (CA) Bee, pg. D4:
What is machaca:
 
Well, it is from a very old Mexican recipe, probably originating far out in the cattle country on the roundup since it calls for a meat base of beef jerky.
 
But the Sanchez make it with shredded bulled beef which is sauteed with bell pepper, tomato and onions and then cooked with scrambled eggs.
   
5 December 1977, Modesto (CA) Bee, pg. C3:
“Machaca” is a traditional dish originating in the northern area of Mexico, made with cooked beef described as resembling little strips rather like a cross between jerky and corned beef, which is stirred into scrambled eggs. One informant said this is often used as the filling for tacos.