The friendship and commerce developing on the southwestern frontier in 1838-1839, were soon interrupted not only by the continued activities of the "cowboys" and such Mexican brigands, as Agatón Quinoñes, but also by the Córdova-Flores incidents which brought a feeling among many in Texas that the renewed trade relations exposed them to new dangers from Mexico, by enabling Mexicans to enter Texas in the disguise of traders, when in reality they were coming for the twofold purpose of keeping the Indians in a hostile attitude toward the Texans, and of obtaining information which would be helpful to their government.[39] 

In the fall of 1839 there began to appear on the frontier two marauding parties of Mexicans. One was headed by Agatón Quinoñes and the other by Manuel Leal. They were ostensibly government customs guards, but were really bandits and cutthroats, banded together for the purpose of pillaging and robbing the unguarded trader, who, according to Mexican law was a smuggler engaged in illicit traffic.

Throughout the six-year period following the revolution, there was a great deal of bitterness engendered on both sides of the Río Grande. Frequent blind alarms of Mexican invading armies, of blockading cruisers, and of devastating Indian raids, produced great excitement and confusion. "In reality," reported a newcomer to Texas in the fall of 1839, many of these alarms were "only the fear of the new immigrants, who pack up at the first suspicious rumor and take flight [from the frontier] to Houston, and even farther to New Orleans, furnishing on the way the terrible descriptions that gradually sounded as if the Turks were in the country."[40]  The frequency of such rumors of a Mexican force concentrating upon the Río Grande caused the editor of the Telegraph and Texas Register to declare in his columns that "the rumor of another invasion by Mexico appears to be dying away, like a thousand idle rumors of a similar character, that preceded it;"[41]