Nothing confirms such a comment relating to war against the Confederacy.
In fact, Federal revenues did fall in 1861, by 11% from $56 million in 1860 to $50 million, then rose 21% in 1862 and doubled in each of the following years.
So Federal government revenues were in no way the major issue they quickly became in the Confederacy.
In his state of the Union report of December 5, 1859, President Buchanan’s Secretary of the United States Treasury issued his report stating that for fiscal year 1859, the total revenue of the US Treasury was $88,090,787. This was misleading, because $28,185,000 was ‘income’ from government borrowing. The actual total revenue from tariffs, and sale of public lands was $53,486,000. Tariff revenue contributed 92% of the total revenue of the country.
But the Congress spent $69,071,000, which was 29% more than it took in.
The value of total US exports for the year was $278,392,000. The value of the exports grown or produced in the South was 74% of the total.
In order to understand the contribution of Southern agriculture to the trade, and thus tariff and taxation structure of the entire country, the following chart shows the percentage of the total value of exports contributed by the South for the year of 1859:
U. S. Department of Commerce
International Transactions and Foreign Commerce
Agricultural Production of the South
Yearly Detail 1859
Value of : Cotton $161,434,000
Tobacco 21,074,000
Rice 2,207,000
Naval stores 3,694,000
Sugar 196,000
Molasses 75,699
Hemp 9,227
Other 8,108,000
___________
Total $196,797,926
Value of Southern manufactured 4,989,000
Cotton exports
Value of cotton component of Northern 3,669,000
Manufactured cotton exports (60%) ___________
$205,455,926
Percentage of Southern Production to
the total US exports for 1859 of
$278,392,000. 74%
Your observation that in 1862 and subsequent years federal revenues increased is because Lincoln initiated an income tax (the first time in U.S. history) and borrowed up a storm. The taxes and the loans were responsible for any increases.
Interesting subject.