The American elm cultivar Ulmus americana 'New Harmony' was raised by the Maryland Agricultural Research Service and released by the United States National Arboretum in 1995, along with 'Valley Forge'.

'New Harmony' proved the most successful U. americana cultivar in the US National Elm Trial, averaging a survival rate of 85.5% overall.

[1] 'New Harmony' is considered by some to have a more desirable form than 'Valley Forge' as it grows vertically on its own with a minimum of early training.

The original parent tree (located on a roadside in Ohio) is already over 20 m high, with a slightly greater crown spread.

[4] In the trials at U C Davis, the trees remained free of leaf curling aphids (Eriosoma), unlike its U. americana stablemates 'Valley Forge' and 'Princeton'.