What inspired the poet Robert Burns to write "Tam O' Shanter"?

Answer 1

It was a local story. The poem first appeared in the Edinburgh Magazine for March 1791, a month before it appeared in the second volume of Francis Grose's Antiquities of Scotland, for which it was written. Robert Riddell introduced Burns to Grose. According to Gilbert Burns, the poet asked the antiquarian to include a drawing of Alloway Kirk when he came to Ayrshire, and Grose agreed, as long as Burns would give him something to print with it.

Burns wrote to Grose in June 1790, giving him three witch stories associated with Alloway Kirk, two of which he said were 'authentic,' the third, 'though equally true, being not so well identified as the two former with regard to the scene'. The second of the stories was, in fact, 'Tam o' Shanter'. This is Burns's prose sketch of it to Grose:

'On a market-day, in the town of Ayr, a farmer from Carrick, and consequently whose way lay by the very gate of Alloway kirk-yard, in order to cross the River Doon, at the old bridge, which is almost two or three hundred yards farther on than the said old gate, had been detained by his business till by the time he reached Alloway it was the wizard hour, between night and morning.

Though he was terrified with a blaze streaming from the kirk, yet as it is a well known fact, that to turn back on these occasions is running by far the greatest risk of mischief, he prudently advanced on his road. When he had reached the gate of the kirk-yard, he was surprised and entertained, thorough the ribs and arches of an old gothic window which still faces the highway, to see a dance of witches merrily footing it round their old sooty black-guard master, who was keeping them all alive with the power of his bagpipe. The farmer stopping his horse to observe them a little, could plainly desern the faces of many old women of his acquaintance and neighbourhood. How the gentleman was dressed, tradition does not say; but the ladies were all in their smocks; and one of them happening unluckily to have a smock which was considerably too short to answer all the purpose of that piece of dress, our farmer was so tickled that he involuntarily burst out, with a loud laugh, 'Weel luppen, Maggy wi' the short sark!' and recollecting himself, instantly spurred his horse to the top of his speed. I need not mention the universally known fact, that no diabolical power can pursue you beyond the middle of a running stream. Lucky it was for the poor farmer that the river Doon was so near, for notwithstanding the speed of his horse, which was a good one, against he reached the middle of the arch of the bridge and consequently the middle of the stream, the pursuing, vengeful hags were so close at his heels, that one of them actually sprung to seize him: but it was too late; nothing was on her side of the stream but the horse's tail, which immediately gave way to her infernal grip, as if blasted by a stroke of lightning; but the farmer was beyond her reach. However, the unsightly, tailless condition of the vigorous steed was to the last hours of the noble creature's life, an awful warning to the Carrick farmers, not to stay too late in Ayr markets.'

Answer 2

Maybe he was inspired by a particularly fetching hat.

Answer 3

Malt Whiskey.