From Ohio Archaeological and Historical Quarterly, Volume XIV, 1905, page 444:
ORIGIN OF THE PHRASE, “KEEP THE BALL ROLLING.”
THOMAS J. BROWN, WAYNESVILLE.
About the year 1840, it was the custom in some sections when a political campaign was on, to work off a surplus of enthusiasm by constructing a huge ball, say 8 to 12 feet in diameter, and covered, at least in some instances, with stout leather so it would stand a great deal of rough treatment. This ball was filled with most anything that would give bulk, and a proper degree of weight, and yet leave it somewhat pliable so as to save it from too much friction; then several persons would roll it along to a political convention. By the way, all large political meetings were called “conventions” in those days, and every man that went was a self-constituted delegate, or a pole raising, or even from one township or county to another when it would be rolled on to the next county by a relay of fresh enthusiastics.
I remember seeing a picture of one of these balls, more than fifty years ago, being rolled along, while the men were supposed to give utterance to the sentiment, “This ball we roll, with all our soul.”
From The Graham Journal of Health and Longevity, Volume 5, Issues 1-25,[No. 16. Vol. Ill], AUGUST 3, 1839, page 263:
AN ANECDOTE.—JUST IN TIME.
A young physician having tried in vain to get into practice, at last fell upon the following expedient to set the ball rolling: He sprang upon his horse once a day, and drove at full speed through the village : after an absence of an hour he would return and carry with him some of his instruments—thinking if he could impress his neighbors with the opinion that he had practice, they would begin to place confidence in his ability....