During the Texas Revolution, the citizens of Gonzales, Texas famously created the Come And Take It flag. Do we know if this phrase was chose to intentionally echo King Leonidas' reply to Xerxes in antiquity, or was this an independant creation? Would the Texian citizens of Gonzales have been aware of the Thermopylae story, and were they intentionally drawing parallels?
Henry Stuart Foote in his "Texas and the Texans" published in 1841 states that The famous "COME AND TAKE IT FLAG" from the battle of Gonzales is actually in reference to the battle of Fort Morris which occurred during the American Revolution. At Fort Morris Colonel John McIntosh and his 200 or so men were besieged by a much larger British force. When the leader of the British force approached the fort he passed a written letter to the fort demanding it's surrender. Col. McIntosh responded with "Come and take it". Because of a skirmish that occurred in the area the day before and Col. McIntosh's resolute reply the British withdrew. The incident became quite famous and McIntosh was rewarded by the state of Georgia after the war with a sword bearing the inscription "come and take it". McIntosh went on to serve as a general in the war of 1812 and was quite famous in the American South. The flag in question was made by Sarah Dewitt, out of her daughter Naomi's wedding dress. Sarah had come to Gonzales from Missouri with her Husband Green Dewitt who was also a veteran of the war of 1812. "The old 18" who first hoisted the flag were as far as I am aware all from the Southern United States and were no doubt aware of this story. The leader of the Mexican Cavalry who were sent to retrieve the cannon was a Lt. Castañeda. Lt. Castañeda reported that when the Texian forces under Col. Moore and his Gonzales volunteers attacked him he asked for a parley with Col. Moore in an attempt to resolve the situation peacefully. Whe Lt. Castañeda asked for the handover of the cannon (as those were his orders) Col. Moore responded by pointing to the cannon and the flag that flew above it by saying "come and take it". While Col. Moore and many of the other Texian rebels were no doubt aware of Thermopylae (many of them were college educated including Moore), by then the Texian force outnumbered the Mexican force and it was obvious the flag was directly referring to the cannon and was simply echoing the sentiment of Col. McIntosh, that they would not be bullied into surrendering their arms, instead they would fight. If your interested Paul Lack's "The Texas Revolutionary Experience: A Political and Social History 1835–1836" Talks in depth about the culture of the Texian rebels and provides some good context about the battle.