While a concerted campaign of use by the commercially-controlled media has given the phrase "conspiracy theory" connotations of craziness and implausibility, this phrase used to have no such overtones. Indeed, the existence of conspiracies was widely acknowledged, even by political leaders.
"the sect of Freemasons grew with a rapidity beyond conception in the course of a century and a half, until it came to be able, by means of fraud or of audacity, to gain such entrance into every rank of the State as to seem to be almost its ruling power".
"The drive of the Rockefellers and their allies is to create a one-world government combining supercapitalism and Communism under the same tent, all under their control... Do I mean conspiracy? Yes, I do. I am convinced there is such a plot, international in scope, generations old in planning, and incredibly evil in intent."
US Congressman Larry MacDonald, killed in the Korean Air Lines Flight 007.
“Since I entered politics, I have chiefly had men's views confided to me privately. Some of the biggest men in the United States, in the field of commerce and manufacture, are afraid of somebody, are afraid of something. They know that there is a power somewhere so organized, so subtle, so watchful, so interlocked, so complete, so pervasive, that they had better not speak above their breath when they speak in condemnation of it.”
Woodrow Wilson (1913) 
the quote continues:
"They know that America is not a place of which it can be said, as it used to be, that a man may choose his own calling and pursue it just as far as his abilities enable him to pursue it; because to-day, if he enters certain fields, there are organizations which will use means against him that will prevent his building up a business which they do not want to have built up; organizations that will see to it that the ground is cut from under him and the markets shut against him. For if he begins to sell to certain retail dealers, to any retail dealers, the monopoly will refuse to sell to those dealers, and those dealers, afraid, will not buy the new man's wares."
- AZ Quotes saved at Archive.org saved at Archive.is
- Introduction to The Rockefeller File (1976) by Gary Allen