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."

Upon what condition may one expect answers to prayer?
How is eternal life bestowed?
Why is the carnal mind enmity against God?
What statement of the redeemed shows that they will remember God's creative power?
How early was this tendency manifested?
What announcement is made under the seventh plague?
How does the Lord regard kindness shown to the poor?

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