From an O.Henry short story:
" In those times cattlemen played at crack-loo on the sidewalks with double-eagles, and gentlemen backed their conception of the fortuitous card with stacks limited in height only by the interference of gravity. Wherefore, thither journeyed the sowers and the reapers--they who stampeded the dollars, and they who rounded them up. Especially did the caterers to the amusement of the people haste to San Antone. Two greatest shows on earth were already there, and dozens of smallest ones were on the way."

CRACK-LOO
Webster's 1913 Dictionary

Definition: \Crack"-loo`\, n. Also Crackaloo \Crack"a*loo`\ .
A kind of gambling game consisting in pitching coins to or
towards the ceiling of a room so that they shall fall as near
as possible to a certain crack in the floor. [Gamblers' Cant,
U. S.]
The definition doesn't seem to fit O.Henry's description, as he says it is a card game.

I got the impression from the passage that these were two different games played by two different social groups. Cowboys played crackloo, while gentlemen played cards.

Bingley

" In those times cattlemen played at crack-loo on the sidewalks with double-eagles--

yup, i am with my dear Mr Bingley-- a double eagle is a silver dollar coin...

i remember kids 'pitching pennies' as a gambling game..

you had to toss the penny so that it touched a wall, the winner was the one who's penny landed closest to the wall...

The double eagle was a $20 coin. The eagle was the highest named denomination of US currency.

http://www.asseenontv.com/prod-pages/gold_double_eagle_coin.html?gid=