The best one can do.
1851. We put our horses out at their level best, and, as I had rather the best one of the two, I kept before.—M. L. Byrn, ‘An Arkansaw Doctor,’ p. 87.
1869. How comes it that the friends of F. A. Marcy did their level best … to secure the defeat of Mr. Francy?—Hartford Courant, Oct. 4 (Bartlett).
