"As civil rulers, not having their duty to the people before them, may attempt to tyrannize, and as the military forces which must be occasionally raised to defend our country, might pervert their power to the injury of their fellow citizens, the people are confirmed by the article in their right to keep and bear their private arms."
"The prohibition is general. No clause in the Constitution could by any rule of construction be conceived to give to Congress a power to disarm the people. Such a flagitious attempt could only be made under some general pretense by a state legislature. But if in any blind pursuit of inordinate power, either should attempt it, this amendment may be appealed to as a restraint on both."
"The best we can hope for concerning the people at large is that they be properly armed."
"If the representatives of the people betray their constituents, there is then no recourse left but in the exertion of that original right of self-defense which is paramount to all positive forms of government, and which against the usurpations of the national rulers may be exerted with infinitely better prospect of success than against those of the rulers of an individual State. In a single State, if the persons entrusted with supreme power become usurpers, the different parcels, subdivisions, or districts of which it consists, having no distinct government in each, can take no regular measures for defense. The citizens must rush tumultuously to arms, without concert, without system, without resource; except in their courage and despair."
"[The Constitution preserves] the advantage of being armed which Americans possess over the people of almost every other nation...(where) the governments are afraid to trust the people with arms."
"Before a standing army can rule, the people must be disarmed; as they are in almost every kingdom in Europe. The supreme power in America cannot enforce unjust laws by the sword; because the whole body of the people are armed, and constitute a force superior to any band of regular troops that can be, on any pretense, raised in the United States. A military force, at the command of Congress, can execute no laws, but such as the people perceive to be just and constitutional; for they will possess the power, and jealousy will instantly inspire the inclination, to resist the execution of a law which appears to them unjust and oppressive."
"What country can preserve its liberties if its rulers are not warned from time to time that their people preserve the spirit of resistance? Let them take arms."
There's more quotes from the founding fathers and their contemporaries online. Safe to say, you're incorrect. The 2nd amendment certainly was to oppose a congressional tyranny.