Depicts the seal of the United Mexican States.

The Seal of the United Mexican States is a modified version of the national coat of arms, with the addition of the full official name of the country Estados Unidos Mexicanos, in a semi-circular accommodation in the upper part of the seal. Current and past Mexican peso coinage have had the seal engraved on the obverse of all denominations.

The coat of arms depicts a Mexican golden eagle perched on a prickly pear cactus devouring a rattlesnake. To the people of Tenochtitlan this would have strong religious connotations, but to the Europeans, it would come to symbolize the triumph of good over evil (with the snake sometimes representative of the serpent in the Garden of Eden).

At the center, the image of the reverse of a Republican coin, 8 Reales 1824 (KM# 376), Durango mint, assayer R.L.; at the upper side, parallel to the coin frame, the legend NUMISMATIC HERITAGE OF MEXICO; on the left side, the Mexican mint mark, while on the right field is the $100.

In 1823 coins of the recently created Mexican Republic began to be minted. In that year it was decreed that the national emblem would be included on the reserve sides of all coins and that the reserve side of silver coins would display an image of a Phrygian cap with the word FREEDOM on the front and Republican shiners on the back. The original die-cutters were stamped by José Guerrero and used in Mexico’s Durango and Guanajuato mints. The Republican shiners are the reason Mexicans ask 'Eagle or Sun?' when they toss a coin.

The Phrygian cap is a soft conical cap with the top pulled forward, associated in antiquity with several peoples in Eastern Europe and Anatolia, including Phrygia, Dacia and the Balkans. In early modern Europe it came to signify freedom and the pursuit of liberty through a confusion with the pileus, the felt cap of manumitted (emancipated) slaves of ancient Rome. Accordingly, the Phrygian cap is sometimes called a liberty cap; in artistic representations it signifies freedom and the pursuit of liberty.