"I will be the first president in modern history to be outspent in his re-election campaign."
That's President Obama speaking—or anyway, whoever writes his fundraising letters—as quoted in today's USA Today.
That's probably not true. Most accounts credit John Kerry with outspending George W. Bush in 2004. Be that as it may, the key variable in President Obama's sentence is the word "modern." The modern era of campaign finance begins in 1976, when post-Watergate disclosure laws first applied to presidential elections.
(That era is ending as we speak, as those same laws dissolve under the impact of recent court decisions authorizing limitless and undisclosed spending by independent campaign entities.)
Before 1976, we are in a very different world, a world in which we know amazingly little about how much campaigns spent and who financed them.
Perhaps you've seen the below chart, compiled by Mother Jones magazine.
Nifty, ain't it? It's also almost 100% guesswork, at least for the period before 1976, and certainly for the period before 1925.
A 1925 law imposed the first disclosure rules in American history. All contributions over $100 were supposed to be disclosed. But since Congress never got around to providing any enforcement mechanism for the law, it was effectively disregarded. Was a briefcase containing 1000 $50 bills a $50,000 contribution, which must be disclosed? Or was it a series of $50 contributions, each of which could be given anonymously? Congress did not say, and it never created a regulatory to clarify.
And before 1925, we are in a world of total murk.
The Mother Jones chart cites a 1974 book by George Thayer titled "Who Shakes the Money Tree?" I tracked down and read a used copy. Thayer's is a lively journalistic account, thinly sourced and very far from authoritative. It also fails to deal with two key facts about 19th and 20th century campaign finance:
1) Through most of the 19th century, probably the most important source of party finance was not donations from rich businessmen, but assessments on the salaries of government patronage hires. The (very!) gradual shift away from patronage hiring after the 1880s and the scare given the business community by William Jennings Bryan in 1896 altered those realities for the 20th century.
2) But even in the 20th century, American campaigns were surprisingly labor—rather than capital-intense—and the labor was volunteered, typically by union members on the Democratic side and by chambers of commerce and the like on the Republican. For that reason, it did not matter very much if (as probably happened) Tom Dewey outspent Harry Truman in 1948. The most important donations were not denominated in dollars, but in hours.