Installation was defective (on my XP computer) with original version and 1.10 version . Trouble was solved by applying latest patch 1.17a.
Latest patch is 1.10 on official page "ageod.com/products/343/details/American.Civil.War.:.The.Blue.and.the.Gray."
However on this forum, latest is 1.17a "ageod-forum.com/showthread.php?27035-AACW-Patch-1-17a-Official-Legacy-November-21-2012" with a dead link. Thanks to user Rafiki, correct link is "ageod-forum.com/forumdisplay.php?f=107". Can links be updated as this game is still sold ?