The Mexican postal system has its roots in the Aztec system of messengers which the Spanish adopted after the Conquest. A postal service was established in 1580, mainly to communicate between the viceroyalty of New Spain with the motherland Spain. During the 18th century, Spain established a formal postal system with regular routes. In 1856, Mexico issued its first adhesive postage stamps, with "district overprints", a unique feature among postal systems worldwide, employed to protect from theft of postage stamps.

In 1891, the postal and stamp issuing authority was created as an administrative division of the Secretaría de Comunicaciones (Secretariat of Communications). It was called Servicio Postal Mexicano (Sepomex). In 1901, the Dirección General de Correos (General Direction of Mail) was made a separate government agency. The Palacio de Correos de Mexico is used since 1907 as main post office.

The Mexican Revolution and ensuing Civil Wars (1910–1920) resulted in numerous provisional and local stamps issued by the factions in control of different areas of the country.

Colonial period

The postal system of Mexico may be said to have begun with the Aztecs, who operated a system of messengers; they worked well enough that Hernán Cortés continued using them after the 1521 conquest.Manuel Carrera Stampa, "El Correo en Mexico/The Mail in Mexico," in La Filatelia Mexicana, Artes en Mexico, No. 96 (1967), pp. 15, 18. After 1579, the right to operate the posts was farmed out to members of the nobility, who were known as "Correo Mayor de la Nueva España". The most important part of their operation was the route between Mexico City and Veracruz.

In 1742, the administrator of posts in Madrid was ordered to improve the Mexican system, resulting in the 1745 establishment of a weekly post between Mexico City and Oaxaca, followed in 1748 by a monthly service to Guatemala. In 1765 the Spanish crown bought back the rights to the postal service, effectively "nationalizing" the posts.

During the Colonial period and continuing up to the introduction of adhesive stamps, letters were typically sent collect, the postage to be paid by the recipient upon arrival. The covers, or envelopes in which the letters were sent, were stamped by hand with the name of the originating town, and typically with a number representing the charge for postage, e.g., "3" for 3 reales. Occasionally, mail was sent postage pre-paid, in which case the envelope would be marked "Franca" or "Franco" or "Franqueado." According to Yag & Bash (1965), some handstamps (on undated covers) date to the 1720s and the earliest known stamped postmark on a dated cover is a Veracruz mark from 1736.Yag & Bash, pp. v–viii,68 (Mexico "est. 1721"), 135 (Vera Cruz "1736"). See also Tizon and Guinovart, Prefilatelia española; estudio de las marcas postales de España y sus dominios de Indias, siglos XVIII y XIX (earliest known postal cancel is Veracruz stamp used 1736-1739 - "Esta marca es las mas antigua conocida hasta la feche del Nuevo Mundo."); Soler & Llach auction catalog, June 19, 1991, Barcelona (letter dated August 8, 1739, with Veracruz postal mark). Yag and Bash researched the Chapman records, and found these numbers of post offices:

Year Principal Branch 1824 17 338 1846 45 440 1854 47 430 1868 47 431 1875 54 241

Most post offices, principal and branch, had handstamps.

Covers from the Colonial period up until the third quarter of the 1800s typically showed only the addressee's name and city; a street address was not written. These letters were not delivered to the addressee. Instead, the letters would be held at the local post office and advertised on posted lists or in newspapers. Many of the recipients were well known businessmen or politicians. Towards the end of the 19th century, larger cities employed postmen to deliver the mail.Similar procedures were used in the United States. See Statutes of 1825-1851 regarding advertising of unclaimed letters

Independence and early republic

Mexico declared independence from Spain on September 16, 1810. This resulted in the long Mexican War of Independence which ended in 1821, and which eventually led to the creation of the short-lived First Mexican Empire. Agustín de Iturbide was the first and only emperor. Two years later, he was deposed by the republican forces. In 1824, a republican constitution was adopted, creating the United Mexican States with Guadalupe Victoria as its first President.

In the 1820s both the British and French began packet service to Veracruz. A British postal agent operated at Veracruz 1825–1874 and at Tampico from around 1840 to 1876. While both were supplied with British stamps, only the Tampico stamps were used (obliterator "C76"). The British service ran continuously until 1914, while French service ended in 1835, was restored in 1862 as the Ligne de Mexico and continued until 1939.

Next to the Mexican, British and French post offices and agents, Mexico had a good number of forwarding agents, most of which operated in the 19th century. Some towns and the agents therein as noted by Ken Rowe:

Acapulco: Foster; Guys & Doty; P.M.S.S. Co. Guaymas: Robinson Matamoros: Erhard, Putnam & Co; Uhde & Co. Mazatlan: Copman & Lomer; Kennedy; Talbot, Parrot (US Consul); Scarborough & Co.; Smith & Mason Mexico City: Sengstack & Schutte; de Drusina & Co. Monterey: Bach Schonfeld Y Ca. Tampico: Baumbush, Magnus & Co.; Droege Y Ca.; Hohls, Muller & Co.; Montluc Vera Cruz: Braune, Busing & Co.; Hargous; Hoffman Y D'Oleire; Manning Basildon & Co.; Manning, Marshal & Co.; Martinez, Perret and Co.; Smith

Classic stamp period 1856–1874

Just as there is no consensus on what constitutes "classic stamps" in general, there is no agreement on what is the "classic period" for stamps of Mexico. In 1926, Samuel Chapman in his The Postage Stamps of Mexico, referred to the "provisional period" as running from 1856 to 1868.Chapman In 1983, Schatzkès & Schimmer published a study of the Cancellations of Mexico from 1856–1874, but they did not specifically call that the "classic period." Pulver in his Introduction to the Stamps of Mexico (1992) included a chapter entitled "Classic Era 1856–1883." Including 1883 as the end of the classic period apparently is based on the fact that the district overprints continued to that year.Follansbee p. 96. However, the only stamps Pulver actually discussed in his "classics" chapter were issued before 1874, which year marked a fundamental change in the appearance of Mexico's stamps.Pulver pp. 7–20. Others view the classic period as extending to 1900 or even later.

How to define the "classic" period thus necessarily is subjective. This article will treat the classic period as running from 1856 to 1874. Before 1874, most of the stamps were locally designed and produced, often with crude or "primitive" workmanship and imperforate or poorly perforated, characteristics that make the stamps charming and popular with philatelists.An exception was the 1864 Juárez issue, also printed by the American Bank Note Company in New York. See Minkus New World-Wide Postage Stamp Catalog (1974 ed.), Mexico, nos. 15–18. In May 1874, Mexico issued a group of stamps designed and printed by the American Bank Note Company in New York,See Minkus New World-Wide Postage Stamp Catalog (1974 ed.), Mexico, nos. 64–70. which were professionally designed and printed using steel engraving, and issued with perforations. These stamps were closely similar in appearance to the contemporary stamps of other countries also manufactured by bank note companies in the United States. Subsequent issues of Mexico, although usually manufactured domestically, were in a similar "modern" style.etiangui ( Enrique Sanchez Garcia ) "Mexico Postal Offices between 1856 - 1883"

District overprints

Virtually all the early stamps of Mexico have district overprints, which were added as an anti-theft device. These overprints came into use in 1856, with the first stamps of Mexico, and continued officially until the end of 1883.Some local postmasters continued to overprint stamps after they were no longer required. Follansbee p. 96.

The Mexican postal system divided the country into about 50 "districts", each of which had a main office and a number of suboffices. The district office ordered stamps from Mexico City, they would be shipped by stagecoach unoverprinted, and then the district office would handstamp each stamp with the name of the district. The overprinted stamps would then both be sold directly to postal customers, and shipped to suboffices.

In theory, only overprinted stamps were valid for postage, but given the error potential of applying the marking to each individual stamp, a small number of unoverprinted uses are known. Also, some offices failed to comply with orders and simply sold their stamps unoverprinted.

In 1864, the system was refined by shipping the stamps from Mexico City with an invoice number and year already overprinted.

Sometimes the district office's overprint included a number designating the suboffice for which the stamps were intended, and occasionally suboffices applied their own handstamps. Larger offices had several different designs of handstamp in use; Mexico City used five different devices to handstamp the stamps of 1856, each with a different appearance, while the districts of Guadalajara, Guanajuato, Puebla, Querétaro, and San Luis Potosí each had three devices.

The color of the district name was almost always black, but red, blue, and violet overprints are known. For a period in 1858, the postmaster of Zacatecas, who had fled the city for Aguascalientes to escape the fighting during the Reform War, but had left his handstamp, wrote in "Zacatecas" by hand.

For many years, philatelists were mystified by the overprints, until Samuel Chapman, a British businessman living in Mexico, took an interest and researched the postal archives. His 1926 book, since reprinted, includes extensive detail on the shipments to the various districts.

Many of the overprints are rare, and command high prices among specialists in Mexican stamps. They have also been forged.

Postal cancellations

After stamps were introduced in 1856, some post offices created new cancellation marks, while others used their existing handstamps bearing the name of the town for years to cancel the new stamps, so that very old handstamps can be found on stamped covers.

Postage stamps

Hidalgo issues 1856 and 1861

President Don Ignacio Comonfort, authorized the prepayment of postage using adhesive stamps by decree of February 21, 1856. New regulations were drawn up and were supposed to be published on July 15, but problems with the engraving delayed this until July 31. On August 1, 1856, Mexico issued its first postage stamps. The design, a portrait of Miguel Hidalgo y Costilla, the parish priest who led an unsuccessful bid for Mexican independence in 1810, reflected the reform politics of the Comonfort government. The stamps were somewhat crudely engraved and imperforate. Five values were issued from 1856 to 1859: ½ real, 1r, 2r, 4r, and 8r. The stamps usually, but not always, had district overprints with the name of the district post office.

Quantities produced according to Follansbee: ½ real blue – 825,573 1 real yellow – 1,425,275 2 reales green – 1,629,773 4 reales red – 157,189 8 reales violet – 100,784

In 1861 the stamps were reissued in new colors on variously colored paper. As in the first issue they were issued both with and without district overprints,Follansbee nos. 1–12.Scott Mexico, nos. 1–12. but in lower numbers.

Quantities produced according to Follansbee: ½ real black on buff – 194,280 1 real black on green – 821,116 2 reales black on pink – 925,573 4 reales red on yellow, orange – 103,675 8 reales black on red brown – 62,762

A study of the 1856 and 1861 issues, with information on the district overprints from Chapman's book is on Jesper Andersen's site.