According to the July, 1904, Monthly Bulletin of the International Bureau of the American Republics,[11] the Blalock Mexico Colony was granted, “...new concessions…by which the organization is authorized, to establish on the land it owns, under the name ‘El Chamal’, in the municipality of Santa Barbara, State of Tamaulipas, an agricultural and industrial colony.” The stipulations bound the Blalock Mexico Colony to settle on the Chamal Hacienda within two years from the establishment of these concessions. The Colony was required to settle 100 families totaling not less than 250 people. It would have to pay a fine of $100 pesos “in bonds of the public debt” for each family under 100 that was not settled.[12]

The corporation was required to settle the colonists, “...upon alternate lots, leaving a lot of 10 hectares between settlers, so that the Mexican Government may on its own account establish in the intervening lots colonists of Mexican nationality, who will be entitled to acquire the land at the same price charged to the company’s colonists… "[13] The Mexicans must be "peaceable and law-abiding people." The concessions spelled out what constituted a Mexican family. These Mexican families were to be given or allowed to purchase one or more plots of land for cultivation in addition to a site for a residence. The site for a residence was to have an area of at least 2,000 meters.

The colony concessions would last ten years and included, “...exemption from military service; exemption from all kinds of taxes, with the exception of municipal taxes and the stamp tax; personal and un-transferable exemption from import duties on agricultural implements, tools and fixtures, machinery, building materials for houses, furniture in use, animals for draft and breeding purposes, all destined for the colony...”[14] It also exempted export duties on products raised by colonists.

The entire text of the Blalock Mexico Colony concessions contract was printed in Spanish in the Periodico Oficial, XXVII, Numero 86 Del Gobierno del Estado Libre y Soberano de Tamaulipas [the State of Tamaulipas official government newspaper], published in Victoria on July 18, 1903. The publication recorded the legal concessions contract.[15] An English concession document was compiled by using the Spanish concessions contract and concession information printed in English in the 58th Congress, House of Representatives Monthly Bulletin of the International Union of American Republics printed in 1904,[16] (see Appendix H). This report provided information about the Blalock Mexico Colony and some of the “new concessions” granted to them by Mexican government.