Was James written before Acts?
In order to date any book, we must consider what we know about the author and the clues that might date the book.
The author of the book of James is debated as there are several James in the Bible. The name "James" derived from the Greek form of the name Jacob. Though the name is common in Jewish society, the author’s greeting is of one who is well-known to his audience. He calls himself a bond-servant, which is a term the apostles often used to refer to themselves. If we consider that Jude’s reference to being the brother of James (Jude 1) is the same James who wrote the book of James, it narrows down the field a bit.
James the Son of Zebedee
This James was the brother of John. He was killed in AD 44 (Acts 12:2). Usually, it is argued that this is too soon for the Book of James to be written because the scattering that started in Acts 8:4 barely began. Yet he can’t be completely ruled out. If it was this James, then he is not related to the Jude who wrote the book of Jude.
James, the Son of Alphaeus
He is mentioned in Matthew 10:3. He had a brother names Joses, which "Jude" is another form of the same name (Mark 15:40). He was also called James the Less, likely because he was younger than the other apostle James, the son of Zebedee, who was the brother of John. There are two passages that mention a Judas who is related to James: Luke 6:16 and Acts 1:13. How they are related is not stated though most assume it is Judas the son of James; however, it could be a brother.
James, the Brother of Jesus
This James is another possibility (Matthew 13:55). He did have a brother named Judas. He was a leader in the church, so he was well-known (Galatians 1:19). Scholars note that the letter from the church in Jerusalem and the book of James are worded in a similar style (Acts 15:23-29).
The audience appears to be Jewish Christians ("The twelve tribes scattered abroad" - James 1:1). The book refers to the assembly as a synagogue (James 2:2). It uses Old Testament characters to illustrate points (James 2:23,25). It refers to Abraham as “our father.” It uses a Hebrew term for God (James 5:4). And it alludes to the climate in Judea (James 5:7). All of these would hint that the Book of James was likely written before Gentiles entered the church in large numbers.
The Book of James is considered one of the earliest letters written, mostly because of its strong Jewish character and the lack of mentioning Gentile Christians. The numerous parallels between James and Romans, lead some to conclude that Paul was familiar with James and that it was written before the book of Romans (A.D. 57). The reference to “some from James” in Galatians 2:12 could be taken as some were misusing James’ letter, which would mean that it was written before the Book of Galatians (A.D. 49).
Often a date from A.D. 45 to 49 is given, but this would mean that a date of A.D. 43 to 44 can’t be completely ruled out either.
The Book of Acts was written during Paul's first imprisonment, which means Acts was written in A.D. 63.