The last straw is an idiom that means the final problem, setback, or source of irritation in a series that causes one to finally lose patience or for something to stop working. It is a shortening of the proverb “it is the last straw that breaks the camel’s back”, which has an Old Testament sound about it, but is not found in the Bible. The Oxford Dictionary of Quotations lists it as a ‘mid 17th century proverb’, but does not provide any supporting evidence for that view.
The earliest citation of the phrase that I can find is from The Edinburgh Advertiser, May 1816: “MR. BROUGHAM remarked, that if it [a tax on soap] were only 3d. a head, or 4d. and 5d. upon the lower orders, yet straw upon straw was laid till the last straw broke the camel’s back.”
Some authorities suggest that the phrase is a variant on an older proverb ‘it is the last feather that breaks the horse’s back’. That may be so, but the earliest I can find for that is after 1816, also from The Edinburgh Advertiser, in November 1829: “It may be very well for Mr. O’Connell, in his own exultation of heart, to ascribe the success of the Catholic Relief Bill to his ‘agitation;’ but the fact is, that ‘agitation’ was only the cause of Emancipation in the same sense in which it is true that the last feather breaks the horse’s back.”
The phrase is often used to describe a situation where a seemingly minor or trivial event causes a sudden and strong reaction, because it comes after a series of previous difficulties or annoyances. For example, “She had been unhappy at work for a long time, but the last straw was when they asked her to work on weekends without extra pay.” The phrase can also be used to refer to the final problem that causes something to stop functioning or collapse, such as “The engine had been making strange noises for a while, but the last straw was when it caught fire on the highway.” The phrase can be modified by adding adjectives like ‘final’, ‘ultimate’, or ‘very’ to emphasize the finality or severity of the situation, such as “The final straw was when he cheated on her with her best friend.” or “The very last straw was when the roof collapsed during the storm.”
