If justification is an event, when does it happen? Lutherans, Methodists, and Calvinists believe that justification is an event (as opposed to the Roman Catholic church and the Orthodox church who believe it is a process). If justification is an event, when does it happen? Is it at the moment of conversion, at baptism, or at some other time?
According to most independent, fundamentalist Baptists, (and to the best of my knowledge, the groups that you mentioned) justification is a one-time event that happens at the moment of conversion, when a sinner repents on his or her sins and puts their faith in Christ for salvation.

This would be in line with a Calvinist view.  Justification is a result of salvation, and is something granted freely as the gift of salvation, apart from any works of man.

The very same Wikipedia article that you linked to outlines the relationship between Justification and Sola Fide, for those denominations that subscribe to the view that salvation is by faith alone.  

This article covers more groups independently, rather than lumping protestants entirely into a group, and may provide more clarity on how different denominations view the topic.