There are a number of different factors that will affect the ability of a foreign-educated lawyer to successfully land a job with a U.S. law firm, and some of the biggest issues are discussed here.
The primary factor that determines whether a person can get a job at a law firm in the United States is whether that person can work legally there. Permission can be broken into three classes: no working permission, working permission for a limited period of time, and full working permission. Absent some special skill that a law firm needs, persons without working permission will find it nearly impossible to obtain a job with a United States law firm. (I would like to meet someone who has obtained a job, even though he/she did not have working permission. Please contact me and tell me how you did it so that I can let other people know how to engage in successful searches.)