Final answer:
The claim that John Brown first attacked pro-slavery forces in Texas is false; he and his sons' first violent actions against pro-slavery settlers occurred near Pottawatomie Creek in Kansas during the 'Bleeding Kansas' conflict.
Step-by-step explanation:
The statement that John Brown and his sons first attacked pro-slavery men in Texas is false. John Brown's first notable act of violence against pro-slavery forces took place near Pottawatomie Creek in Kansas, not Texas. On the night of May 24, 1856, Brown, accompanied by his four sons and three other men, attacked the homes of pro-slavery settlers, which resulted in the brutal executions of five men. This event is known as the Pottawatomie Massacre and occurred in the context of the Bleeding Kansas conflict, a series of violent civil confrontations in the United States between 1854 and 1859 which emerged from a political and ideological debate over the legality of slavery in the proposed state of Kansas.