“...hereby authorized and required to cause the number of the inhabitants within their respective districts to be taken; omitting in such enumeration Indians not taxed, and distinguishing free persons, including those bound to service for a term of years, from all others; distinguishing also the sexes and colours of free persons, and the free males of sixteen years and upwards from those under that age....”
Enumeration was to begin on 2 August 1790. The marshals were given the power to appoint assistants at their discretion to help make the returns. Assistants were given nine months to complete the task and make their returns to the marshal. Both were to be bound by oath before beginning their service.
So just how much did they earn?
Assistants received one dollar for every 150 people returned who resided in the country and $1 for every 300 residing in towns with populations of more than 5000 people. The marshal was allowed to adjust the assistant’s compensation as he saw fit for sparsely populated divisions--not to exceed $1 for every 50 people. Before making his return, the assistant was required to:
“...cause a correct copy, signed by himself, of the schedule, containing the number of inhabitants within his division, to be set up at two of the most public places within the same, there to remain for the inspection of all concerned....”
Producing and posting those copies garnered the assistant an additional four dollars.
Compensation for the marshals, designated by the congressional act, ranged from $200 for the Connecticut marshal to $500 for the Virginia marshal.
All in all, an estimated 650 enumerators counted 3,929,214 resident at a cost of $44,000.
Flash forward to 2010.
The enumerators of 2010 actually only visited households who couldn’t be reached by the US Postal System or who did not return the census questionnaire mailed to them. These 21st century enumerators received a 164 page Enumerator Manual. In it were topics like “Who’s Who in NRFU” and “Safety.” In addition to daily pay, they were also reimbursed for their mileage.
Go get some paper and a pen and ink, and some helpers if you need them, and go and ask these six questions of every household and count every person in each household in your district. Send the aggregate numbers back by 1 September 1791 or you won’t get paid.
But I digress...back to 2010.
According to a 2012 Census Bureau report, there were 47,000,000 households in the 2010 census who did not respond to the mailings and had to be visited by an enumerator. 
Now, for a wee bit o’ math using the Bureau's numbers:
308,745,538 people ÷ 131,704,730 households = 2.34 people per household
2.34 people X 47,000,000 households = 109,980,000 people.
The cost of the 2010 census: $12,900,000.
From barely a cent per resident in 1790 to eleven point four cents per resident in 2010.
In 1790 there were six questions each enumerator asked; in 2010, there were 10 you answered yourself unless you were a Nonresponse Follow Up (NRFU) household. In that case an enumerator asked them.
220 years and four additional questions later, the greatest country on earth failed to conduct a census more efficiently than the marshals did on horseback, dodging bears and wolves, in 1790.
I think the 1790 marshals did it better.
 “2010 Census Nonresponse Followup Contact Strategy Experiment,” United States Census Bureau, accessed 7 October 2018, https://www.census.gov/library/publications/2012/dec/2010_cpex_174.html