Review:

A refreshing balance of sour lemon and sugar, laced with London dry gin and lengthened with soda. Some know this cocktail as a Tom Collins, understandably so, but a Tom Collins is based on old tom gin, while a John Collins is based on London dry gin. I borrow the wise words of David A. Embury (below) to address this confusion on our Tom Collins page.

Variant:

In his 1948 The Fine Art of Mixing Drinks David A. Embury says, "Originally there were two brothers only in the Collins family - Tom and John. During recent years, however, numerous cousins have appeared on the scene - Pedro, Pierre, Sandy, Mike, Jack, the Colonel and several others whose first names have not yet been officially recorded in the baptismal registry."
Captain Collins - with Canadian whisky
Colonel Collins - with bourbon whiskey
Dutch Collins or Genever Collins (aka Phil Collins) - with genever/jenever/Hollands
Jack Collins - with calvados
Jock Collins or Sandy Collins - with Scotch whisky
Joe Collins or Vodka Collins - with vodka
John Collins - with London dry gin
Jose Collins or Pepito Collins - with tequila
Mike Collins or Ronan Collins - with Irish whiskey
Pedro Collins - with light white rum
Pierre Collins - with cognac/brandy
Pisco Collins - with pisco
Rum Collins - with aged rum
Tom Collins - with old tom gin
Whiskey Collins - with bourbon/rye whiskey

History:

It would appear that the Collins morphed from the Gin Punch, a popular drink of the day and its creation and name are attributed to John (or possibly Jim) Collins, head waiter at Limmer's Hotel on Conduit Street in London during the late 1800s. The 'coffee house' of Limmer's Hotel was a true dive bar, popular with sporting types during the 19th century and famous, according to the 1860s memoirs of Captain Gronow (a Victorian writer of four observational tomes) for its Gin Punch as early as 1814.

John Collins is immortalised in an 1892 limerick written by Frank and Charles Sheridan about John Collins:

My name is John Collins, headwaiter at Limmer's,
Corner of Conduit Street, Hanover Square,
My chief occupation is filling brimmers
For all the young gentlemen frequenters there.
Mr. Frank always drinks my gin punch when he smokes.

Charles and Frank Sheridan, 1892

It could be that the special gin-punch for which John Collins of Limmer's was famous became known as the Tom Collins due to its being made with old tom gin.

In his 1882 Bartenders' Manual, Harry Johnson includes recipes for a John Collins based on Holland Gin (genever) and a Tom Collins with old tom gin.

JOHN COLLINS.
(Use an extra large bar glass)
1 table-spoonful of sugar;
5 to 6 dashes of lemon juice;
1 wine glass full of Holland gin;
4 or 5 small lumps of ice;
Open a bottle of plain soda water, pour this into the ingredients, mix up well, remove the ice, and serve.
Careful attention must be paid when mixing the soda water with the above, not to let the foam of it spread over the glass.

TOM COLLINS
(Use an extra large bar glass)
Three-quarters table-spoon of sugar;
3 or 4 dashes of lime or lemon juice;
3 or 4 pieces of broken ice;
1 wine glass of Old Tom gin;
1 bottle of plain soda water;
mix up well with a spoon, remove the ice, and serve.
Attention must be paid not to let the foam of the soda water spread over the glass.

Harry Johnson, Bartenders' Manual, 1882

Thos. Stuart's 1904 Stuart's Fancy Drinks and How to Mix Them includes a Tom Collins with old tom gin and a John Collins with "gin" – assumed to be London dry gin.

Tom Collins.
(Use an extra large bar glass)
¾ table-spoonful of sugar.
3 or 4 dashes of lime juice.
3 or 4 pieces of broken ice.
1 wine-glass of Old Tom gin.
1 bottle of plain soda.
Mix well with a spoon, strain and serve.
Attention must be paid not to let the foam of the soda spread over the glass; this drink must be drank as soon as mixed.

John Collins' Gin.
(Extra large bar glass)
1 table-spoon sugar.
About 5 dashes lemon juice.
1 wine-glass gin.
5 or 6 small bits of ice.
1 bottle plain soda.
Mix well, remove the ice, and serve.

Thos. Stuart, Stuart's Fancy Drinks and How to Mix Them, 1904

Nutrition:

One serving of John Collins contains 184 calories