During the summer of 2018, Facebook, Google, and Twitter created policies and implemented transparent archives that include U.S. political advertisements which ran on their platforms. Through our analysis of over 1.3 million ads with political content, we show how different types of political advertisers are disseminating U.S. political messages using Facebook, Google, and Twitter's advertising platforms. We find that in total, ads with political content included in these archives have generated between 8.67 billion - 33.8 billion impressions and that sponsors have spent over $300 million USD on advertising with U.S. political content. We are able to improve our understanding of political advertisers on these platforms. We have also discovered a significant amount of advertising by quasi for-profit media companies that appeared to exist for the sole purpose of creating deceptive online communities focused on spreading political messaging and not for directly generating profits. Advertising by such groups is a relatively recent phenomenon, and appears to be thriving on online platforms due to the lower regulatory requirements compared to traditional advertising platforms. We have found through our attempts to collect and analyze this data that there are many limitations and weaknesses that enable intentional or accidental deception and bypassing of the current implementations of these transparency archives. We provide several suggestions for how these archives could be made more robust and useful. Overall, these efforts by Facebook, Google, and Twitter have improved political advertising transparency of honest and, in some cases, possibly dishonest advertisers on their platforms. We thank the people at these companies who have built these archives and continue to improve them.