Please note that Mommsen uses the AUC chronology (Ab Urbe Condita), i.e. from the founding of the City of Rome. You can use this reference table to have the B.C. dates
From: The History of Rome, by Theodor Mommsen
Translated with the sanction of the author by William Purdie Dickson
Democratic Agitation under Carbo and Flaccus
The distribution of land was at an end; the revolution went on. The revolutionary party, which possessed in the allotment-commission as it were a constituted leadership, had even in the lifetime of Scipio skirmished now and then with the existing government. Carbo, in particular, one of the most distinguished men of his time in oratorical talent, had as tribune of the people in 623 given no small trouble to the senate; had carried voting by ballot in the burgess-assemblies, so far as it had not been introduced already;(5) and had even made the significant proposal to leave the tribunes of the people free to reappear as candidates for the same office in the year immediately following, and thus legally to remove the obstacle by which Tiberius Gracchus had primarily been thwarted.
5. Cf. IV. II. Vote by Ballot
The scheme had been at that time frustrated by the resistance of Scipio; some years later, apparently after his death, the law was reintroduced and carried through, although with limiting clauses.(6)
6. The restriction, that the continuance should only be allowable if there was a want of other qualified candidates (Appian, B. C. i. 21), was not difficult of evasion. The law itself seems not to have belonged to the older regulations (Staatsrecht, i. 473), but to have been introduced for the first time by the Gracchans.
Do you see any typos or other mistakes? Please let us know and correct them
Reference address : https://www.ellopos.net/elpenor/rome/4-03-revolution-gaius-gracchus.asp?pg=10