The founders of the United States were liberals. They believed that men (yes, white property owning men) had a God-given right to determine the direction their lives could take free from outside interference. In their day, the most likely source of interference and the one they revolted against, was an unresponsive and corrupt central government headed by a hereditary monarch. For the first hundred years of the nation's existence, that perspective was maintained effectively as the sole means by which to measure individual liberty and government authority. By the 1880s though, another threat to personal liberty arose in a way not fully contemplated by the founders: the perpetual corporation.
In the founders' day corporations were rarely used and novel methods of agglomerating capital to take on tasks and disburse the risk of loss in a venture which could not normally be carried by a single owner/operator. They were single-purposed and short-lived. Governments also had great authority to exercise control over the effects a corporation had within its community. Some of the founders recognized the possibility of such entities growing beyond the ability of small governments to control them but that foresight could only go so far.
By the last quarter of the 19th century though, laws had changed to allow the growth of corporate behemoths of size, scope, and influence beyond any of the founders' worst nightmares. Accordingly, a new major threat to the liberty of the individual became a force in American life. The question of whether or how to contend with that threat effectively defines much about modern American politics. Simply stated, the only entity capable of bringing to bear enough resources to assure that the people are not abused by the whims, desires, greed, need, what-have-you of the modern corporation was a larger, more commercially active government at all levels. It required the proper functioning of the former great threat to manage the dangers posed by the abuse of the latter great threat.
The goal is still to protect individual liberty; the Liberal Ideal. The means to do so, requires one to trust in the good graces of two recognized devils. Somewhere along the line, because corporations are private property, the label conservative has stuck to those who still see government as the greater threat to liberty while liberals, who long ago fought a revolution to limit government interference in the liberty of the people, now look to it as the main protector of that same liberty.
Perhaps the greatest threat to liberty is the failure of adequate labels to show we all take different roads to get to the same place.