national captioning institute, which is responsible for its caption content and accuracy. visit ncicap.org] [captions copyright national cable satellite corp. 2015] >> join us each saturday at 8:00 p.m. and midnight eastern for classroom lectures from across the country on different topics and eras of american history. lectures in history are also available as a podcast. visit our website -- c-span.org/history/podcasts or download them from itunes. >> each week, american artifacts visits use em's and his workplaces. established by congress in 19 -- in 1820, the united states botanic garden is the oldest garden in america. next we will take a tour and learn about collections of this museum, originally proposed by president washington. >> welcome to the united states botanic garden.

my name is ari novy. i am the executive director of the united states botanic garden. our motto could be plants plans, plans, but our official mission is to demonstrate the importance of plants to the public and their value. today we will take some time and i will show you a little bit about the botanic gardens and introduce you to the stars of the conservatory and those other wonderful plants we have here today. right now we are standing in a room called the garden courts. i always liked to orient people to the garden court initially when we come in, and one of the most important elements are the two spike heads you see in front. very prominently displayed. the first things you see. they are incredibly important for us, because they represent part of our historic collection. the u.s. botanic garden came into existence in some ways as a permanent institution in 1842 when the united states exploring

expedition returned from a four-year voyage in the pacific ocean, at the behest of congress, mainly doing surveying, but also picked up a whole bunch of really me -- really meet artifacts, including plants. so when the expedition returns they had about 150 fascinating tropical and subtropical plant species, many of which had never been on the north american continent, and this was deemed a very, very valuable. this collection of plants was immediately recognized as important by congress. funds were appropriated for a temporary greenhouse structure to house them while a permanent u.s. botanic garden could be built to house the collection and expand on the collection. we still have, to this day, a couple of plants that are direct descendents all those plants and the spy kids that we just looked

at the one on the left is one of the original plan -- plants. subsequent to its introduction to the united states, it has actually become a relatively important tree species in terms of ornamental trees, in the tropical parts of the united states, and specifically in southern florida. as with most things in life, it is often quite instructive to change one's perspective. so we made sure to include a canopy wall and the higher levels of the jungle house, and it's absolutely wonderful to get amongst the top of the trees into the canopy, cb wonderful plants that grow at this level. and also looked down, look straight ahead at the leaves the flowers, the seeds. it provides a really fantastic

interesting environment that is different from what you would see at the ground level. so, i want to thank you for taking time to visit with us at the botanic gardens. the u.s. botanic garden is an absolutely amazing resource. we are open 365 days a year. we are absolutely free from 10:00 until 5:00. no matter what season, time of year, there is always something in bloom something to see and, hopefully something you have not seen before. >> sunday at 6:30 p.m. eastern former cia chief jonna mendez recalls the story of husband and

wife kgb spies. they infiltrated the cia and gathered information through the use of sex in the 1950's. one popular washington, d.c. swingers club frequented by the spy couple counted at least 10 cia staffers and a u.s. senator as members. that is 6:30 p.m. eastern here on american history tv. up next on american history tv historian kenneth boling recounts the story of how washington, d.c., became the capital of the united states. he spoke about how the location was chosen and the figures that shaped the city's creation, and the plan that architect peter charles l'enfant presented to president george washington in 1791. this is about one hour. >> i don't have any visuals