We can say that Jesus died FOR ALL MEN.Salvation by faith for those living before Christ.
"This meaning of dikaiosune, right action, is frequent also in Paul's writings, as in all five of its occurrences in Romans 6; Rom_6:14, etc. But for the most part he uses it of that gracious gift of God to men whereby all who believe on the Lord Jesus Christ are brought into right relationship with God. This righteousness is unattainable by obedience to any law, or by any merit of man's own, or any other condition than that of faith in Christ....The man who trusts in Christ becomes 'the righteousness of God in Him,' 2Co_5:21, i.e., becomes in Christ all that God requires a man to be, all that he could never be in himself Because Abraham accepted the Word of God, making it his own by that act of the mind and spirit which is called faith, and, as the sequel showed, submitting himself to its control, therefore God accepted him as one who fulfilled the whole of His requirements, Rom_4:3.... (Vine)
Useful to know. Abraham and obviously others were made right with God. We read the same in Paul's letter to the Hebrews.
Those that came before Him and those that came after.
In some way, Jesus atoned for the sins of every man that wishes to serve God.