Here are just a few that I have found thus far.
In a very real sense, it will not be one man going to the moon it will be an entire nation. For all of us must work to put him there.
John F. Kennedy
Coming together is a beginning; keeping together is progress; working together is success.
Henry Ford
“Great discoveries and improvements invariably involve the cooperation of many minds. I may be given credit for having blazed the trail, but when I look at the subsequent developments I feel the credit is due to others rather than to myself.”
Alexander Graham Bell
“Competition has been shown to be useful up to a certain point and no further, but cooperation, which is the thing we must strive for today, begins where competition leaves off.”
Franklin D. Roosevelt
Feel free to post any more you find.