It was at the end of the 1820’s that riding corsets…

…were developed specifically to allow freedom of movement.

(Featured Extant 1820’s riding corset.  Note the high cut above the hip and flexible laces along he side of the body to allow for movement in all directions)

Below: riding ensembles with which the riding corset was worn – 1815 and 1818.  Note they were riding sidesaddle (see section on “1890 Riding Outlaw” regarding history of women riding sidesaddle vs astride)