The curve, part one: 1925–1954 — the machine takes the county

1925 – 1954, by census

The counts, with their years: Allen County's tractor record in the published Census of Agriculture runs in four steps to its peak. On 1 January 1925: 795 tractors on the county's farms. On 1 April 1940: 1,924 farms reporting tractors, and 2,034 tractors in all — and the 1940 census, which asked the year of each farm's latest-model tractor, shows the fleet's age plainly: 1,013 farms ran a latest model of 1936–1940, 324 a model of 1931–1935, and 569 still ran a tractor of 1930 or earlier, the average latest-model year standing at 1933. On 1 April 1950: 2,581 farms reporting, of the county's 3,582 farms — 72 farms in every 100 — and 3,969 tractors. In the autumn of 1954, in the sample-based county table of that census: 2,575 farms reporting and 4,670 tractors, the county's documented peak — of them 3,600 wheel tractors other than garden tractors, 995 garden tractors, and 75 crawlers.

What the machine displaced: The same censuses count the horse's retreat in their own categories. In 1925, 3,580 of Allen County's 4,038 farms — nearly nine in ten — still reported horses and/or mules. By 1954 the census was classifying farms by class of work power, and of the county's estimated 3,230 farms, 2,150 ran a tractor and no horses or mules at all; 235 ran a tractor alongside horses or mules; 165 kept horses or mules without a tractor; and 680 reported neither. Horse-keeping farms had fallen from nearly nine in ten (1925) to about one in eight (1954), and the mixed farm — tractor and team together — was already the smallest working class but one. The state frame runs the same way: Indiana farms reporting tractors numbered 8,871 in 1920, 22,817 in 1925, 40,402 in 1930, 68,447 in 1940, 89,458 in 1945, 106,037 in 1950, and 119,898 in 1954.

The garden tractor's separate rise: Inside the 1954 totals sits a second machine age beginning: garden tractors stood on 623 Allen County farms in 1950 (635 machines) and on 980 farms four years later (995 machines) — the small tractor of the lawn and the acre lot multiplying even as the farm fleet itself approached its peak, a line the lawn-and-garden trade would build on for the rest of the century.

Sources:

1. U.S. Census of Agriculture: 1925, Part I — Indiana County Table II (tractors on farms, 1925) and County Table VI (farms reporting horses and/or mules, 1925).
2. Sixteenth Census of the United States: 1940, Agriculture, Volume I — Indiana County Table X, items 64–69: tractors on farms, 1 April 1940 (farms reporting, number, and year of latest model).
3. U.S. Census of Agriculture: 1954, Volume I — Indiana County Table 5: tractors, farms reporting and number, for 1954 and 1950; farms by class of work power, 1954; garden and crawler tractors, 1954 and 1950; the county's estimated farm counts of 3,230 (1954) and 3,582 (1950).
4. U.S. Census of Agriculture: 1959, Volume I — Indiana State Table 4: the state series of farms reporting tractors, censuses of 1920 to 1954.