Nominating conventions came into being in the 1830s, after Andrew Jackson and his ilk turned party politics into a more egalitarian affair. The elite caucuses that had once chosen presidential candidates gave way to more inclusive mass gatherings where delegates styled themselves as representatives of the people. By the time the Republican Party formed in the 1850s, nominating conventions had become significant political events in the life of the country. Journalists, artists, and photographers documented the appearance and actions of the delegates and the spirit and style of the gatherings.
This particular artist’s drawing shows the meeting of the Republican Party in Chicago in 1860, when the young anti-slavery party nominated Abraham Lincoln for the presidency. The Republicans went to the trouble to build a special hall for the convention, a vast domed wooden structure that they called the Wigwam. (It stood at the corner of Lake and Wacker and was reportedly destroyed by fire in the late 1860s.) Notably, the illustration shows a mainly female audience crowding the galleries to follow the proceedings. (Women would not gain the right to vote until 1920.)
Faced with the likelihood that the federal government would sanction the spread of slavery into the West and strengthen its legal underpinnings everywhere in the US, those participating in the Republican convention believed it to be an event ‘on which the most momentous results are depending.’ ‘No body of men of equal number,’ the convention chair proclaimed, ‘was ever clothed with greater responsibility than those now within the hearing of my voice.’
The Republicans, though only a northern regional party, were intent on dislodging the dominant Democratic Party, which they did that November, against all odds.
Image from this source.