might and main

[…] I found myself hanging on the skysail-yard, holding on might and main to the mast; and curling my feet round the rigging, as if they were another pair of hands.

1849, Herman Melville, “Chapter XVI”, in Redburn: His First Voyage. […], 1st American edition, New York, N.Y.: Harper & Brothers, […], →OCLC

When the sunlight threads the pine-gloom he is fighting might and main / To clinch the rivets of an Empire down.

1907, Robert W[illiam] Service, “The Younger Son”, in Songs of a Sourdough, Toronto, Ont.: William Briggs, →OCLC, stanza 4, page 61

Mr. Winkle, catching sight of a lady's face at the window of the sedan, turned hastily round, plied the knocker with all his might and main, and called frantically upon the chairman to take the chair away again.

1836 March – 1837 October, Charles Dickens, “(please specify the chapter name)”, in The Posthumous Papers of the Pickwick Club, London: Chapman and Hall, […], published 1837, →OCLC

Thinking that we were about to be taken up under the act for the suppression of vagrancy, we flew out of the house, sprang into a canoe before the door, and paddled with might and main over to the opposite side of the lake.

1847 March 30, Herman Melville, “The Hegira, or Flight”, in Omoo: A Narrative of Adventures in the South Seas; […], London: John Murray, […], →OCLC, page 246

The good mothers, like Burns’s matron, are plying their needles, making "auld claes look amaist as weel’s the new;" while the domestics, or help (we prefer the national descriptive term), are wielding, with might and main, their brooms and mops, to make all tidy for the Sabbath.

1852, Catherine M. Sedgwick, “The Sabbath In New England”, in John Seely Hart, editor, The Female Prose Writers of America: With Portraits, Biographical Notices, and Specimens of their Writings

"I feel just like studying with might and main," she declared as she brought her books down from the attic.

1908 June, L[ucy] M[aud] Montgomery, chapter XXXI, in Anne of Green Gables, Boston, Mass.: L[ouis] C[oues] Page & Company, →OCLC

Another horrific attack on tourists to Dublin in the city centre and in the height of summer. Gardaí are doing their job with might and main.

2023 August 15, Senan Molony, “Give McEntee an accountability holiday on street crime–for now”, in Irish Independent, page 8