Keep the ball rolling
Maintain a level of activity in and enthusiasm for a project.
The American expression 'keep the ball rolling' was preceded by the similar, now archaic, British phrase 'keep the ball up'. They had much the same meaning, the earlier one alludes to keeping a ball in the air, i.e. conveying the notion of keeping an activity going. This was used figuratively by the radical social philosopher Jeremy Bentham, in a letter to George Wilson in 1781, referring to his efforts to keep a conversation going:
"I put a word in now and then to keep the ball up."
Bentham may be long dead but continues to be radical. He didn't opt for the traditional coffin, buried six feet under, but willed that his body be stuffed, mounted and put on display. It is exhibited in a cabinet at University College, London (although the severed head has now been removed). As a student at the University in the 1960s I was one of many who took the opportunity to open the cabinet doors to see Bentham peering back through the waxy glass - quite disconcerting.
The 'keep the ball rolling' version of the phrase owes its origin and popularity to the US presidential election of July 1840. That election is widely regarded as introducing all the paraphernalia of present-day elections, i.e. campaign songs, advertising slogans and publicity stunts of all kinds. The unpopular incumbent President Martin Van Buren was pitted against Whig candidates, General William Harrison, a war hero who had fought against the Shawnee Indians at Tippecanoe, and John Tyler. The Whig candidates revelled in a folksy 'cider-drinking, log-cabin, men of the people' image and adopted the first known political slogan - 'Tippecanoe and Tyler, too'. A song of the same name was considered to have sung Harrison into the presidency:
Don't you hear from every quarter, quarter, quarter,
Good news and true,
That swift the ball is rolling on
For Tippecanoe and Tyler Too.
Harrison's campaign literature referred to Victory Balls. These weren't, as we might expect, dance parties that celebrated his famous victory, but ten-foot diameter globes made of tin and leather, which were pushed from one campaign rally to the next. His supporters were invited to attend rallies and push the ball on to the next town, chanting 'keep the ball rolling'.
See other phrases that were coined in the USA.