In the form of willow bark, yes, it was. Salicylic acid, the primary compound in aspirin, is also found in willow bark, which has been used therapeutically for 3500+ years.
Nice knowledge! A helluva lot of alcohol was consumed then too, probably even “prescribed” to take with a tincture for whatever the person was suffering from. Willow bark + alcohol + blood letting likely killed more than a few.