By the time of his sudden death at the age of 50 he was credited with the construction of one quarter of Russia's railroads,[2] his personal net worth was estimated at 31.4 million roubles.

[1] This type of relationship between statesmen and Jewish entrepreneurs was common in post-emancipation Russia; Tolstoy by the time of his death (1867) allegedly owned half a million roubles in Polyakov shares.

[7] "Services" mentioned by Witte actually were running a vodka distillery on wastelands of Tolstoy's estate,[8] and the "launch" was granted as a contract to build the Grushovka-Aksay local rail line, owned by the Don Cossack Host and completed in 1863.

Polyakov pioneered fast-track railroad construction schedules, introducing new standards of project management promoted by his new ally in the government, minister Pavel Melnikov.

Kursk-Kharkiv-Azov mainline (780 verst, commissioned in two stages in July and December 1869) was built in a record time of 22 months; it provided the first reliable rail link for Donets Basin coal mines where Polyakov had substantial interests.

[12] The state unconditionally guaranteed bond issues by railroad companies, ensuring steady flow of new investors; during the concession period, the owner-operator was entitled to all the profits of the venture.

[8] In addition to newly built roads, Polyakov acquired existing ones, including Russia's first commercial railroad from Saint Petersburg to Tsarskoye Selo (purchased in 1880).

[9] Samuel Polyakov's Saint Peterburg home was the former Countess Laval palace at 4, English Embankment, a four-storey neoclassical landmark designed by Thomas de Thomon; in the 1820s-1830s the building housed literary salons attended by Vasily Zhukovsky, Alexander Pushkin and Adam Mickiewicz.

[16] Polyakov retained the original neoclassical interiors intact; after him it passed to his son Daniel and was eventually bought by the state for the Governing Senate offices.

[4] Shortly before the murder of Alexander II Polyakov, Horace Günzburg and Nikolai Bakst succeeded in securing royal approval to establish the Society for Crafts and Agricultural Labor[17] (Russian: Общество Ремесленного Труда, ОРТ), a national Jewish interest group which eventually grew into World ORT network.

[18] Its initial purpose was to train Jews in work crafts, creating skilled workforce for the needs of rapidly developing capitalism inside the Pale of Settlement.

The public, enraged by the accident that nearly destroyed the House of Romanov, connected mismanagement of the Kursk-Kharkiv-Azov railroad to Polyakov and, particularly, "credited" him with substandard, too thin gravel ballast pads that failed to cushion track vibrations as they were supposed to.

[15] Polyakov's railroad ventures of the Russian-Turkish war period provide the principal setting for The Engineers (Russian: Инженеры), a novel by Nikolai Garin-Mikhailovsky published in 1907.