The Class 290 was a development of the earlier Class 270 locomotives, studied under the Rete Adriatica; it kept the wheelbase, but replaced the boiler with a slightly bigger one, with a minimally coned rear ring. Its construction was continued under the new FS management, which made it one of its twelve standard designs; it was the last and most successful 0-6-0 Italian locomotive.
The class was built by several Italian and foreign manufacturers, between 1899 and 1913. The first 30 locomotives were fitted with a two-axle tender, with a coal capacity of 3,400 kg (7,500 lb) and a water capacity of 8,000 l (1,800 imp gal; 2,100 US gal); the subsequent ones were fitted with the three-axle tender that would see widespread service under the FS (especially behind the Class 625 and Class 640 locomotives).
The first 112 locomotives were classified as Class RA 350 bis (with running numbers between 3631 and 3742); of these, 52 were taken over by the FS in July 1905 upon formation, while the other 60 were taken over by the new Strade Ferrate Meridionali (Southern Railways), a rump of the RA, until its incorporation with the FS in July 1906.