The French probably invented mens braces, they were strips of ribbon fixed into buttonholes called brettelles' around the time of the French Revolution. Most of these brettelles' were made from silk or satin and it was usual to decorate them with logo's or other symbols.
The first suspenders had a H-back, so two lines vertically from shoulder to trousers. In the 18th century they crossed over in a X-back and finally since 1850 finished in a Y-back, which is still around today.
In this era the mens braces were fastened to trousers with buttons. Only in 1894 an American invented a metal clasp to attach the braces to the trouser.
By the way please note that trousers for ordinary men were made without belt loops till the 1920's. After the 1920's people started to wear belts. Nevertheless mens braces are still quit popular, especially by business men.