When was the book of James written?

Some actually pretty good discussion here on its dating. The long comment by Moremon is good, though he appears to be plumping for at least the possibility of a relatively early date within a pseudepigraphal James by conflating Raymond Brown's dating schema and Dale Allison's.

Pytine's comment is also good, bringing Kloppenborg into the mix.

First? Yes, absolutely, it's pseudepigraphal. The absence of second-century church fathers quoting it, except a possible but not guaranteed reference by Irenaeus, plus even into the third, and a bit into the fourth, centuries, later fathers still raising an eyebrow about its authenticity, are markers.

Second? At the tail end of the first century, many New Testament scholars note that Paul went into eclipse. So, no author at that time would have good reason for trying to make "James" look Pauline. And, yes, despite the "show me your faith," etc., and early-Lutheran era Martin Luther's perplexment, it is Pauline in look.

But, get several years into the second century? Different story. Assuming a still relatively strong Ebionite movement before the Bar Kokhba revolt, with Paul surging back into prominence again, an author trying to make a "James" look Pauline would have incentive to write, just like an author trying to deal with church governance in a Jesus movement facing an ever-longer delay in the eschaton would have reason to write the Pastorals.

Liotorg raises the issue of, dating aside, whether James had more of an indirect oral dependence on the authentic Paulines, and the first set of pseudeipigraphs, Colossians and Ephesians, or whether there was even a literary dependence. He says it doesn't affect dating, but IMO, a written dependence would tend to push James' dating later, in that you need more time for more copies of an ancient manuscript to circulate more.

Per other commenters, Craig Evans and James Tabor are wrong in arguing for an early date. Of course, Tabor argues for a Jesus dynasty, which commenter Dramatic Ad ignores, which means he has motive to argue James wrote in the 50s.