All Cigarette Cards of RDR2
The Stranger Mission from Phineas T. Ramsbottom called "Smoking and Other Hobbies" is necessary to collect all the cards, as some of them only appear if you have accepted that quest. You can find Phineas after the Story Mission "Who is Not Without Sin". To update your list, mail the cards from the Post Office to Phineas, and this will update your progress shown under Options, Progress, Compendium, Cigarette Cards.
How to find Cards
Cards spawn in fixed locations, but can also be found at random in Premium Cigarette Packs, that are rarely found as loot, at Merchants or inside some residences.. Those packs will give any of the 144 cards, so they can be used for a lucky fill on a missing item. If you get duplicates, you may sell them for profit.
Cigarette Cards Location Maps RDR2