Which racecourse was the first ever to use starting stalls?

Hello.

The Bahr starting gate was the first to keep each horse in a separate
stall. Bahr starting stalls were first used at Hawthorne in Chicago,
in 1928-29.


"....starting stalls were introduced on a regular basis at Hawthorne,
in Chicago, in 1929, and spread rapidly..."
source: ExclusivelyEquine, cached by Google:
http://66.102.7.104/search?q=cache:7fZT2IY5PQ8J:www.exclusivelyequine.com/isroot/eenew/SiteImages/PDFs/Excerpt_Ringers.pdf+%22starting+stalls+were+introduced&hl=en

"1928...
 * The Bahr starting gate is introduced at Hawthorne."
source: hawthorneracecourse.com
http://www.hawthorneracecourse.com/hawthorne_news/history.php

Also see:
"...the Bahr starting gate, which keeps each horse in a separate stall..."
://www.google.com/search?hl=en&lr=&q=%22bahr+starting%22+%22separate+stall&btnG=Search


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search strategy:
"starting stalls were introduced "

I hope this helps.