Adam Clarke on Galatians 1:21

Afterwards I came into the regions of Syria, etc. - The course of the apostle's travels, after his conversion, was this: He went from Damascus to Jerusalem, and from Jerusalem into Syria and Cilicia. "At Damascus the disciples took him by night, and let him down by the wall in a basket; and when Saul was come to Jerusalem, he assayed to join himself to the disciples;" Act 9:25, Act 9:26. Afterwards, when the brethren knew the conspiracy formed against him at Jerusalem, they brought him down to Caesarea, and sent him forth to Tarsus, a city of Cilicia, Act 9:30. This account in the Acts agrees with that in this epistle.