Most of the following excerpts give a sense of the critical-thinking movement that came to prominence in the 1930s. The first and second quotations are included to illustrate that the phrase 'critical thinking' was already in use in education studies by the 1930s. The final quotation is provided to show that the vagueness of the phrase was bothering academics in the 1960s.
N. S. Maddox (1922): 'Educators have long been accustomed to hear that our schools do not teach real thinking.' ('Review of Teaching to Think' The Journal of Educational Research 6 : 265)
A. S. Barr (1931): 'There are probably many classifications in the literature of education, that are more or less indefensible. One learns, for example, that there are four ways (more or less) of getting experience: (1) by participation (or doing); (2) by observation; (3) by reading and conversing with others (the verbal mode); and (4) by reflective thinking. One naturally wonders whether there really are four modes of acquiring experience or whether there are just three modes (that is, from this point of view), and whether the fourth (critical thinking) is not merely a condition necessary for effective operation.' ('Educational Terminology' The Journal of Educational Research 23 : 417)
William W. Biddle (1932): 'Wherein has education failed to produce critical thinking? Education has often been the handmaiden of propaganda. Religious groups, communists, or believers in one-hundred-per-cent Americanism have seen in education an opportunity to indoctrinate students with their particular ideas. ...We must examine the process whereby critical thinking is achieved.' (Propaganda and Education [New York: Bureau of Publications, Teacher's College, Columbia University, 1932], p. 10)
Richard Gadske (1940):
The need for developing more effective critical thinking abilities of high school pupils is generally recognized. This need has been brought to the educational foreground as a result of one of man's great periods of transition. Modern life, during the past several decades, has become extremely complex and greatly enhanced through the medium of invention and discovery. Greatly improved methods of transportation make it possible to travel extensively and within a relatively short period of time. Highly improved ways and means of communication facilitate the exchange of ideas. Modern production and distribution is fostered by widespread advertising. In the light of these penetrating and far-reaching social forces, the citizenry in a democratic society are challenged in their thinking to the limits of their capacities. A society that calls itself democratic, therefore, necessitates the education of individuals who are capable of self-direction and a high degree of critical thinking. (Gadske, Demonstrative Geometry as a Means for Improving Critical Thinking, unpublished doctoral dissertation, Northwestern University [Evanston, Illinois, June, 1940], p. 15)Edward Maynard Glaser (1941): 'American education is freely criticized today because the ability to think critically is not well developed among secondary school pupils and even among college graduates. Many "educated" persons jump to conclusions which are not supported by evidence, are unaware of their own contradictory statements, seem unable to keep their wishes from influencing their interpretation of data or evaluation of arguments, and, in general, do not make sufficient conscious and voluntary effort to establish belief upon a firm basis of evidence and rationality.' (Glaser, An experiment in the development of critical thinking [New York, Teacher's College, Columbia University, 1941], p. 8)
Glaser (1941): 'The development of critical thinking is a desirable outcome of education not only because it contributes to the intellectual and social competence of the individual ..., but also because it helps him to cooperate better with his fellow men. It helps him to form intelligent judgments on public issues and to contribute democratically to the solution of social problems. ... At no time in our history has wider realization of this educational objective been more urgently needed.' (Ibid., pp. 9-10)
Deobold van Dalen (1941): 'A democratic conception of education would require the young to learn progressively, under decreasingly directive guidance, how to think critically, how to judge objectively, and how to act responsibly.... Democracy's ultimate safeguard is the enlightened conscience of the citizen.' ('Civic Competence: Classical or Controversial?' The Social Studies 32 : 246-247)
Frederick George Marcham (1942): 'The whole concept of a democratic society, as it exists and is developing in the United States, rests upon the cooperation of socially alert and active citizens. To bring home to each individual the importance of critical thinking as a prelude to social action is to help to preserve and enlarge the democratic way of life in the United States.' ('The Nature and Purpose of Critical Thinking in the Social Studies', in Teaching Critical Thinking in the Social Studies, ed. Howard R. Anderson, Thirteenth Yearbook of the National Council for the Social Studies [Washington, DC: The National Council for the Social Studies, a Department of the National Education Association, 1942], p. 47)
H. H. Giles and William van Til (1946): 'A third hypothesis is that if community organizations and schools emphasize the need for critical thinking and proof, there can be developed an increased understanding of scapegoating and the use of stereotypes which helps to break down libelous labeling.' ('School and Community Projects' The Annals of the American Academy of Political and Social Science 244 : 40-41)
John Ward Studebaker (1947): 'Critical thinking is our only democratic safeguard against the domination of our thinking and feeling by various organs of mass communication.' ('Social Implications of Modern Science' The Annals of the American Academy of Political and Social Science 249 (1947): 138)
B. O. Smith (1965): 'Under close examination, it became clear to us that it is a vague and ambiguous notion. We found, for example, that many people tend to identify critical thinking with so-called propaganda analysis, or to associate it with wholesale skepticism or even with juvenile negativism of the rebellious adolescent.' -reporting on the Illinois Project on Critical Thinking (quoted from Allen, R. R. and Rott, Robert K., 'The Nature of Critical Thinking. Report from the Concepts in Verbal Argument Project'. Theoretical Paper No. 20.Wisconsin Univ., Madison. Research and Development, Center for Cognitive Learning)
Update (in response to a Facebook comment by Jay Gupta): It's interesting that Smith in 1965 notes a tendency to equate critical thinking with 'propaganda analysis' (or what we might now call 'media literacy'), since that was a focus of critical thinking in the early 1930s (e.g., W. Biddle's 1932 study). It was in reaction to that tendency that some progressivists widened the scope of critical thinking.