What was the date of Constantine's famous Sunday law?

Answer

AD. 321.

What do Catholics say of the observance of Sunday by Protestants?
Of what does God say the keeping or hallowing of the Sabbath is a sign?
What, according to its constitution, is the avowed object of the National Reform Association?
Why were the ancient Sunday laws demanded?
What was shown upon the opening of the first seal?
What was given these martyrs?
By what means were the three Hebrews protected while in the fiery furnace?

Questions & Answers are from the book Bible Readings for the Home Circle