in an effort to reveal her source vice president cheney's chief of staff . she was found in contempt of court and prison for 85 days per it's sunday she talks about her time in jail as well as her new book of what the story/. >> i was in jail because i refused to reveal the identity of a source whom i thought did not want his identity revealed. in our business, as you know protecting sources is the life light of independent journalism. i really felt that unless the people that i routinely spoke to who had access to classified information, unless they could trust me to protect them, my sources would dry up. and eventually, i would just be writing what the government wanted you to write. so i felt this was a question of principle that i did not have much choice. >> sunday night at 8:00 eastern on c-span's " q&a."

>> this year, c-span is touring cities across the country, exploring american history. next look at our recent visit to saint augustine, florida. you are watching american history tv all weekend, every weekend on c-span three. >> we are at the saint augustine lighthouse and museum. this is the location of florida's first lighthouse. there was originally a cotina lighthouse built here sometime in the late 1800s. in the 1700s, it was turned into a functional lighthouse. it was down on the water and after florida became a state they kind of put the money into it and made it into a lighthouse with oil lamps and they realized it was going to fall into the ocean so they started building the current lighthouse that we have today and that was completed in 1874 and the old

one fell into the ocean in 1880. the current tower has been here since 1874. the purpose of the lighthouse here is to serve as a location reminder to all of the ships in the area. each lighthouse has its own individual day mark and night mark. our lighthouse day mark is the black and white stripes with the red type and no other white house can have that. you see those colors and you aren't in saint augustine. our night mark is our lens. we have a original 1874 lansbury and it has three bull's-eyes on it and when they rotate, the beams are 30 seconds apart. it's a steady light with 32nd flashes. that's what it looks like on the ocean. we deserve to let sellers know they are in saint augustine and let them know where the port is so they can be safely guided. the lighthouse comes on every night. as a museum, we maintain that now through volunteers and staff

and donations. we are a nonprofit. we came in and restored the lighthouse and the original keepers house which is from 1876 and we preserved those for future generations of a can see how the lighthouse worked and operated and the weavers that lived here. it was like a military post for them. they and their families lived here and worked day and night. it was a tough job. there are 219 steps to the top of the tower and had to climb up every two or three hours to put oil into the lanterns and clean things off and wind the clock mechanism that kept the lens rotating. it was a rigorous job. we want to keep that commemorated and show people how that works. in addition to being preservationists and taking care of the tower, we launched a lighthouse archaeological maritime program. we have a team of archaeological researchers and they go out and look at shipwrecks in our area.

we want to know what the history of the nation's oldest port is because saint augustine is the oldest city in the country and is the nation's oldest port. they go out and find shipwrecks using a magnetometer, a big metal detector, and then they dive down to those racks -- wrecks and bring up some of the artifacts and we use those to figure out the story behind those ships. as the ships were coming and going, that was the main transportation in and out of saint augustine for hundreds of years so it can tell us a lot about the people coming and going from saint augustine. one time there was a ship wreck every two weeks and saint augustine. there are literally hundreds of shipwrecks off of our coast waiting to be discovered and waiting for us to be able to excavate those. we look forward to the next piece of saint augustine history we will uncover. >> find out where c-span cities tour is going next online at www.c-span.org/cities tour. you are watching american

history tv all weekend, every weekend on c-span three. >> today is the 2015 white house correspondents association annual dinner. watch our live coverage of the event on c-span starting at 6:00 p.m. eastern with a guest arrival on the red carpet. president obama will address more than 2600 attendees in the ballroom in this years entertainment is saturday night live's cecily strong. the white house correspondents dinner starting at 6:00 a.m. eastern on c-span. >> you found one. >> it looks like this one is the ducting for medical payments covered by insurance. >> this we suspect is how a great many people think of adp automatic data processing. the newest text tool of the

internal revenue service and a new dimension in tax administration. but this is the real part of the martinsburg monster. it's unofficial name. nearly everyone in the united states has some concern with this mechanical marvel and its electronic relative. in the remote quarters of the mountains of west virginia, many are in seven other widely scattered areas of the country. the regional service centers. these machines are things of gleaming metal and numerous flashing lights. these are lights which do not, however, spell out the names of stage and screen attractions and their performers. they spell out, in a sense, the federal tax status of millions of taxpayers, business or individuals are. while much goes before and much comes after, most of these complex machines are placed in operation by the simple push of

a finger. >> up next on american history tv yale university professor talks about effect memory and biases had in shaping the historical account of the civil war. he says the south saw their defeat as a result of the northern industrial machine and superior numbers and southerners eventually believe that despite losing the war, they were ultimately victorious in reconstruction. this one our 15 minute event was part of the symposium hosted by the vermont humanities council. >> good morning, everybody. most of you have been in the front. i hope this becomes a discussion of sorts. i wa