As a general rule, these buckles with tines (Tooth type) are considered "civil war" era. Yours is probably from the 1850's however. "Tine" type buckles were popular from the 1840's till the early 1870's. Most were actually used as pants waist adjuster buckles or vest buckles although some WERE used as suspender buckles. I'm not an expert by no means but I have dug them, collected them, and studied them for many years.