Someone asked almost the same question about a week ago, which I answered here, which links back to more info as well in a previous answer.

The TL;DR is: because Election Day wasn't uniform in the early presidential elections in the United States, returns from many states would have already trickled in before November. In a landslide, winners could be projected in the first half of November. In closer elections, it would take longer, but most people would likely know the results within 1-6 weeks after the last polls closed. The main exceptions are 1800 and 1824, which were disputed elections decided by Congress. By 1840, most people would know even the results of close elections within two weeks, and by the 1850s, it was usually the next day or two. Of course, people who didn't care and lived in very remote areas might not find out the news until much later.