Here someone has played a Patch card. A patch covers up a paradox. In this case, a paradox was caused when we saved Lincoln from being assassinated, because that meant that he went on to be president, drastically changing future events.
By patching the timeline, we have set things up so that Lincoln ends up being impeached, so that he is no longer president, and everything else that happens from this point onwards is normal.
You can see on the patch that the patch will be nullified if the Assassination of Lincoln linchpin card is reverted back (i.e. someone makes sure he gets assassinated). In that case the patch is discarded, and the card under it is flipped back to show the same timeline as we started with.
Every time you patch a paradox, you draw a card to add to your hand. When your hand reaches 10 cards, you win the game. So one of the ways to win is to create and patch paradoxes.
