Who first enjoined Sunday-keeping by law?

Answer

Constantine the Great.
NOTES - "The earliest recognition of the observance of Sunday as a legal duty is a constitution of
Constantine in AD. 321, enacting that all courts of justice, inhabitants of towns, and workshops were to be
at rest on Sunday (venerabili die Solis), with an exception in favor of those engaged in agricultural labor. "Encyclopedia Britannica, ninth edition, article "Sunday."
"Constantine the Great made a law for the whole empire (AD. 321) that Sunday should be kept as
a day of rest in all cities and towns; but he allowed the country people to follow their work."-Encyclopedia
Americana, article "Sabbath."
"Unquestionably the first law, either ecclesiastical or civil, by which the Sabbatical observance of
that day is known to have been ordained, is the edict of Constantine, AD. 321."-Chambers' Encyclopedia,
article "Sabbath."

In what language did Isaiah foretell Christ's birth?
16. When the prodigal son, in the parable, repented and turned toward home, what did his father do?
For what is it profitable?
Why did God command Israel to hallow the Sabbath?
What sign was to follow the darkening of the sun and the moon?
How, according to Luke, did Christ answer this question?
How will the righteous ever afterward appear?

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