Tower Hill asserts that this antique apple is named for the famous Civil War general, but that seems unlikely.
My two samples are a medium and a large medium, each with a red blush (translucent to saturated) that almost entirely covers a light yellow. The fruit smells sweetly of cider.
McLellan's flesh, white and fine-grained, has a soft crunch with light cantaloupe flavors, vinous highlights, and a hint of honey. Its delicacy is overwhelmed by a chewy peel. Overall, nicely balanced, though the crunch could be more assertive.
Beech, who thought highly of this apple, traces McLellan to Woodstock, Connecticut about the time of the Revolutionary War. There are published reports of this variety under that name at least as early as 1851, when General George McClellan was in his 20s and still an army captain.
The apple had several names, all but one ("Martin") a variant, including "McClellan," the General's actual name.
My samples may have been a little past their peak for picking and eating.