Of American-English origin, the expression to have an axe to grind (American-English spelling ax) means to have a private reason for doing, or being involved in, something.

It has often been attributed to Benjamin Franklin [note 1]. For example, the New English Dictionary (NED – 1888), as the Oxford English Dictionary was known, mentions “a story told by Franklin” but, curiously, neither the earliest quotation given by this dictionary nor the others are from Benjamin Franklin, who in his autobiography did mention axe-grinding, but in a completely different sense:

Order too, with regard to Places for Things, Papers, &c. I found extremely difficult to acquire. I had not been early accustomed to Method, & having an exceeding good Memory, I was not so sensible of the Inconvenience attending Want of Method. This Article therefore cost me so much painful Attention & my Faults in it vex’d me so much, and I made so little Progress in Amendment, & had such frequent Relapses, that I was almost ready to give up the Attempt, and content myself with a faulty Character in that respect. Like the Man who in buying an Ax of a Smith my neighbor, desired to have the whole of its Surface as bright as the Edge; the Smith consented to grind it bright for him if he would turn the Wheel. He turn’d while the Smith press’d the broad Face of the Ax hard & heavily on the Stone, which made the Turning of it very fatiguing. The Man came every now & then from the Wheel to see how the Work went on; and at length would take his Ax as it was without farther Grinding. No, says the Smith, Turn on, turn on; we shall have it bright by and by; as yet ’tis only speckled. Yes, says the Man; but—I think I like a speckled Ax best. And I believe this may have been the Case with many who having for want of some such Means as I employ’d found the Difficulty of obtaining good, & breaking bad Habits, in other Points of Vice & Virtue, have given up the Struggle, & concluded that a speckled Ax was best.

In fact, the expression to have an ax(e) to grind is from Who’ll Turn Grindstone, a text written by Charles Miner [note 2] and first published in the Luzerne Federalist (Wilkes-Barre, Pennsylvania) of 7^th September 1810 (it corresponds to the earliest quotation that the NED gave and erroneously dated to 1815):

Who’ll Turn Grindstone

When I was a little boy, Messrs. Printers, I remember one cold winter’s morning, I was accosted by a smiling man, with an ax on his shoulder,—“My pretty boy,” said he, “has your father a grindstone?” “Yes sir,” said I. “You are a fine little fellow,” said he, “will you let me grind my ax on it?” Pleased with his compliment of “fine little fellow”—“O, yes, sir,”—I answered, “it is down in the shop.” “And will you my man,” said he, patting me on the head, “get a little hot water?” How could I refuse? I ran and soon brought a kettle full. “How old are you, and what’s your name,” continued he without waiting for a reply. “I am sure you are one of the finest lads that I have ever seen, will you just turn a few minutes for me?” Tickled with the flattery like a little fool I went to work, and bitterly did I rue the day. It was a new ax—and I toiled and tugged, till I was almost tired to death. The school bell rung, and I could not get away,—my hands were blistered, and it was not half ground. At length, however, the ax was sharpened, and the man turned to me, with “Now, you little rascal, you’ve played the truant,—scud to school, or you’ll rue it.” Alas, thought I, it was hard enough to turn grindstone this cold day, but now to be called “little rascal” was too much. It sunk deep in my mind, and often have I thought of it since.
“When I see a Merchant, over polite to his customers, begging them to taste a little brandy, and throwing half his goods on the counter—thinks I, that man has an ax to grind.
“When I have seen a man of doubtful character, patting a girl on the cheek, praising her sparkling eye and ruby lip, and giving her a sly squeeze,—Beware my girl, tho’t I, or you will find to your sorrow, that you have been turning grindstone for a villain.
“When I see a man flattering the people, making great professions of attachment to liberty, who is in private life a tyrant, Methinks, look out good people, that fellow would set you to turning grindstone.
“When I see a man, holding a fat office, sounding ‘the horn on the borders,’ to call the people to support the man, on whom he depends for his office, Well thinks I, no wonder the man is zealous in the cause, he evidently has an ax to grind.
“When I see a Governor, foisted into the chair of state, without a single qualification to render him either respectable or useful,—Alas! methinks, deluded people, you are doomed for a season to turn grindstone for a booby.
“When I see a foreigner expelled from his own country, and turning patriot in this—setting up a PRESS, and making a great ado about OUR liberties, I am very apt to think,—tho’ that man’s ax has been dulled in his own country, he evidently intends to sharpen it in this.”

In 1815 (the year mentioned by the NED), Who’ll Turn Grindstone became the first in the series entitled Essays from the Desk of Poor Robert the Scribe. It seems that it is partly because this title so closely resembled Benjamin Franklin’s Poor Richard’s Almanack [note 3] that the expression has been attributed to the latter author.

Incidentally, in response to the invitation to attend the commemoration of the two hundredth anniversary of the settlement of Norwich, Connecticut, Charles Miner wrote on 17^th July 1859 that he got the idea of such a series from Samuel Trumbull, the son of the editor of the local newspaper in Norwich:

Samuel Trumbull […] was a young man of a good deal of reading, and of ready wit. He wrote several essays under the head of “From the desk of Beri Hesden.” The hint and the name of the essays—“From the desk of poor Robert the Scribe,” I am sure I owed to him.

Notes

1 Benjamin Franklin (1706-90) was one of the Founding Fathers of the United States. A noted polymath, he was a leading author, printer, political theorist, politician, postmaster, scientist, musician, inventor, satirist, civic activist, statesman, and diplomat.
 

2 Charles Miner (1780-1865), editor and publisher, was also a member of the House of Representatives from Pennsylvania.
 

3 Benjamin Franklin first published Poor Richard’s Almanack in 1732. The book, filled with proverbs preaching industry and prudence, was published continuously for 25 years and became one of the most popular publications in colonial America, selling an average of 10,000 copies a year.