Individual Income Tax <3
The tax on individuals' incomes regularly produces the largest amount of federal revenue.
The Payroll Tax
From the 1790s to World War I the largest source of revenue was tariffs. Then it became income taxes.
In the US, tobacco products (particularly cigarettes) are taxed at both the state and federal level. These taxes are not a significant part of the federal revenue, but some states depend on the revenue from cigarette taxes.
Taxes on business gross profits, and on personal gross earnings.
The Federal Government
Google "List of largest companies by revenue."
Wood
US Federal Government
The largest out of the five largest law firms based on annual revenue is Baker & McKenzie in the US. The second is Skadden, Arps, Slate, Meagher, & Flom in the US. The third is Clifford Chance in the UK. The fourth is Linklaters from the UK. And Latham and Watkins in the US is the fifth.
The Federal Government
The major revenue of US comes from their weapon business. They are the largest weapon seller in the world.