From the Committee Report, 19 January, 1829

     This committee report, released by Senator Richard M Johnson of Kentucky, later Vice President during the Van Buren administration, re-affirmed the position taken by the Congress of the United States in 1810, 1815, and 1825, namely, the mail will be delivered on Sundays.  A brief quote from the report:

Let the national legislature once perform an act which involves the decision of a religious controversy, and it will have passed its legitimate bounds. The precedent will then be established, and the foundation for that usurpation of the Divine prerogative in this country, which has been the desolating scourge to the fairest portions of the old world. Our Constitution recognizes no other power than that of persuasion, for enforcing religous observances. Let the professors of Christianity recommend their religion by deeds of benevolence -- by Christian meekness -- by lives of temperance and holiness[.]

     Quoted in "Religion and Politics in the Early Republic: Jasper Adams and the Church-State Debate"  Some pages available at Print.Google.Com.  I suspect the book is more generally pro-religion.  But it does a fair-minded job of blowing many of the more inane "Early Americans Were Legally Christians" balderdash.