Both formerly part of Mr Potter's Museum of Curiosities, they came for sale from the estate of the ceramic artist and passionate collector Candice Groot of Evanston, Illinois.
The Kittens' Wedding, featuring 20 kittens wearing morning suits or dresses of cream brocade complete with parson and altar, was Potter's last large work, completed in 1898. It was loaned to the Victoria & Albert Museum in 2001 for the exhibition The Victorian Vision: Inventing New Britain and subsequently featured in the 2013 book Walter Potter's Curious World of Taxidermy.
It had sold to Groot for £18,000 when the Potter Museum (housed for many years at Jamaica Inn, Bodmin Moor) was dispersed by Bonhams in a memorable sale in 2003.
In suburban Chicago it carried an estimate of $10,000-15,000 but was competed for by two UK phone bidders, exchanging blows in increments of $10,000 each, to $100,000 (£66,700).
A much larger 6ft 3in (1.9m) wide Potter tableau titled Kittens' Tea & Croquet Party had taken £16,000 in 2003. Comprising 37 young felines, 17 seated for dinner, the remainder playing croquet, it met the same two competitors in this latest sale before it was hammered down at $140,000 (£93,400).