The story
Probably from a railway train climbing a length of track sloping uphill (a grade).
Etymology from Wiktionary, CC BY-SA 4.0.
make the grade
Today it means: To prove satisfactory; to be successful or worthy of merit. Full definition →
Today it means: To prove satisfactory; to be successful or worthy of merit. Full definition →
Probably from a railway train climbing a length of track sloping uphill (a grade).
Etymology from Wiktionary, CC BY-SA 4.0.