Consignments.
Prior to August 29, 1856, stamps were only issued in Mexico City. Three consignments to Mexico City were made before eight other districts received their first consignments on August 29. On August 30 another 28 districts followed. One of the implications is that a first day cover from August 1, 1856 could only come from Mexico City. However, you could also consider any cover cancelled on the first day of stamp availability in any one of the districts a first day cover. However, the exact date of availability is often not known.
The stamps were distributed to 59 districts and sub-offices in a total of 893 consignments between August 1, 1856 and April 17, 1861. Mexico City received the last five consignments between April 5 and 17. All other districts received their last consignment of the first issue stamps on or before April 5, 1861.
These consignments were made at quite regular intervals, and it is interesting to note that they were done at a rate of almost 4 per week in the period of validity.
Most stamps were of course used in the largest district, Mexico City. Approximately 13% of the ½ real, 16% of the 1 real, 26% of the 2 reales, 29% of the 4 reales and 24% of the 8 reales were used in Mexico City.
A summary of the quantities sent in all the consignments until April 17, 1861, from Samuel Chapman:
| Year | ½ real | 1 real | 2 reales | 4 reales | 8 reales |
|---|---|---|---|---|---|
| 1856 | 384720 | 372890 | 157500 | 32220 | 36300 |
| 1857 | 86359 | 471280 | 813930 | 43031 | 15943 |
| 1858 | 83160 | 329060 | 402830 | 39060 | 22860 |
| 1859 | 35656 | 137427 | 139770 | 19864 | 11997 |
| 1860 | 20760 | 57800 | 67450 | 13140 | 8760 |
| 1861 | 214918 | 55818 | 48293 | 9874 | 4924 |
| Total sent | 825573 | 1424275 | 1629773 | 157189 | 100784 |
| Returned | -57213 | -20892 | -13438 | -4542 | -6324 |
| Total issued | 768360 | 1403383 | 1616335 | 152647 | 94460 |
Most catalogs use the number sent to the districts as the number issued. I have chosen to subtract the stamps returned for destruction to come up with a number, which more closely reflect how many stamps could have been used, and therefore be the basis for the availability of the stamps today.
It is clear to see that the ½ real was distributed mainly in 1856, before the rate change, and in 1861, when supplies were used to avoid printing more 1 and 2 reales stamps, just before the stamps were replaced by the 1861 issue on colored paper.
A practice, which affected the numbers above to some extent, was the bi-, quadric and octo-section of some of the values, to make up for the lack of lower value stamps. In Zacatecas this practice resulted in the 8 reales stamp being very rare, whereas fractions of a stamp are relatively common. This practice was not officially sanctioned, so the use of split stamps constitutes illegal usage.