An important point of discussion concerning Galatians is the old debate concerning the setting and date of the letter. One set of scholars holds that Galatians was written around the time of Romans and the Corinthian letters, so the mid to late 50s. Others consider it was written around 47–48. Scholars dispute to whom Paul wrote. Those who prefer a later date argue Paul wrote the letter to churches in North Galatia planted on his second Antiochian mission journey (Acts 16:6) or even on his third (Acts 18:23). Such a setting pushes the date to the mid or late 50s. Others who hold an earlier date argue that he wrote it sometime between his first Antiochian mission (Acts 13 – 14) and his second. Another critical factor is whether the visit to Jerusalem in Gal 2 matches the visits to Jerusalem in Acts 11 (the famine visit) or Acts 15 (the Jerusalem Council discussion on Gentile Christians the Law).
It seems to me that the arguments for an earlier date are much stronger than those for the later date. First, the only real evidence of evangelization in the Galatian region is Acts 13 – 14. Acts 16 and 18 suggests Paul passed through visiting churches rather than full on evangelization. Certainly, Luke gives no indication of his evangelization of the northern area. Rather, it seems Paul left it to the Galatians to complete the task. Conversely, Acts 13 – 14 clearly has Paul in Galatia and planting churches. One weakness of this view is that Paul preached the gospel to them first due to illness (Gal 4). Luke says nothing about this, so one can surmise this happened on Paul’s second or third journeys. However, this is not a strong argument because the details of Paul’s evangelization are scant even where Luke does mention it. So, he may have been ill on his first journey at some point, and it is to this Paul is referring.
Second, if Gal 2 is the Jerusalem Council visit of Acts 15, Galatians seems redundant. Acts 15 refers to a letter written to the Gentile churches telling them that they did not need to be circumcised and come under the Law. Silas took this to Antioch. Paul and Silas then traveled from Antioch to the Galatian churches. No doubt they carried the letter. Galatians then would be needless. Rather, the letter from the Jerusalem Church and his presence with them would do the trick. So, it fits better to see Gal 2 as Acts 11 and Galatians preceding the Jerusalem Council.
Third, if the letter comes after the second Antiochian mission journey and before the third, then Paul would surely mention the Jerusalem Collection. In 1 Cor 16, there is a reference to Paul gathering money from the Galatian churches. Yet, Galatians is silent on collecting money. All that is mentioned is Gal 2:10 where the Jerusalem leaders urge Paul to continue to remember the poor, something he is eager to do. While this reference can fit a date after Paul’s second Antiochian journey, it fits nicely with Acts 11 being the Gal 2 journey to Jerusalem. Barnabas is also mentioned, perhaps indicating this is before their split which happened before the second mission trip.
Fourth, some argue that chronology fits a later date. So, it is claimed Jesus died in 33, and Paul’s conversion was in 34/35. He spent three years in Arabia. He then visited Jerusalem 37/38. There is then a fourteen-year span until his second journey to Jerusalem in 51/52, which is the Jerusalem Council visit (Acts 15; Gal 2:1–10). He then travels on his third journey and spends time in Ephesus. He may have written Galatians from there in the mid-50s. However, there are two ways through this. One is to take the fourteen years as inclusive of the three years, the fourteen years being from his conversion. Such an interpretation takes the date to AD 48. An alternative is that Jesus died in 30 and Paul was converted in 32/33, which also takes the date to 48. Hence, the chronology question remains unclear leaving both possibilities open.
All in all, I think the case for South Galatia and a date around 48 a year before the Jerusalem Council makes better sense of the data. It is not a watertight case as the chronology question, the possibility that Gal 2 matches Acts 15, the presence of Titus, the references to later visits to Galatia, and the closeness of themes and style to Romans and the Corinthian correspondence, gives a reasonable case for North Galatia. Thankfully, such a decision is not critical as it does little to change the meaning of the letter.
So, I surmise that the situation was thus: Paul has evangelized the churches of South Galatia (Acts 13 – 14). He has returned to Antioch. Judaizers have entered his churches seeking to convince Gentile converts to Judaize. Paul has heard of this and wrote Galatians to deal with it. Some of these same characters come to Antioch and do the same. Their presence catalyzed Paul’s visit to Jerusalem with Barnabas where the church resolved the issue (Acts 15). After this, Silas and Judas delivered the letter to Antioch. Subsequently, after the split with Barnabas and Mark, Paul took Silas and the letter west to follow up on his Galatians letter. The Judaizers remained an issue after this, but the ‘orthodox’ position of the church is that a new Gentile believer did not require to adhere to Jewish boundary markers to be saved and included in God’s people.