* College is Diverse: There are thousands of colleges and universities, each with different curricula and course requirements. What was a "main assignment" at one school might be very different from another.
* Field of Study Matters: Assignments vary dramatically based on a student's major. An English major's "main assignment" might be an essay, while a science major's could be a lab report.
* 1951 was a Long Time Ago: Educational practices have evolved significantly since 1951. What was considered a "main assignment" then might not be the same today.
To get a better understanding, you need to be more specific about:
* Which college or university are you interested in?
* What field of study was the assignment in?
With more information, we might be able to provide a more helpful answer.