The quotes can be found in XML\NewText\EN_US\CIV5GameTextInfos_Jon.xml. Sorry about the lack of formatting, this is just a direct copy/paste from the current version of the file.
<!-- Dan Quayle Screen -->
<Row Tag="TXT_KEY_DQ_LEADER_NAME_1">
<Text>Augustus Caesar</Text>
</Row>
<Row Tag="TXT_KEY_DQ_LEADER_NAME_1_QUOTE">
<Text>I found Rome a city of bricks and left it a city of
marble.</Text>
</Row>
<Row Tag="TXT_KEY_DQ_LEADER_NAME_2">
<Text>Hammurabi</Text>
</Row>
<Row Tag="TXT_KEY_DQ_LEADER_NAME_2_QUOTE">
<Text>When Marduk sent me to rule over men, to give the
protection of right to the land, I did right and righteousness,
and brought about the well-being of the oppressed.</Text>
</Row>
<Row Tag="TXT_KEY_DQ_LEADER_NAME_3">
<Text>Abraham Lincoln</Text>
</Row>
<Row Tag="TXT_KEY_DQ_LEADER_NAME_3_QUOTE">
<Text>Always bear in mind that your own resolution to succeed is
more important than any other.</Text>
</Row>
<Row Tag="TXT_KEY_DQ_LEADER_NAME_4">
<Text>Charlemagne</Text>
</Row>
<Row Tag="TXT_KEY_DQ_LEADER_NAME_4_QUOTE">
<Text>Let my armies be the rocks and the trees, and the birds in
the sky.</Text>
</Row>
<Row Tag="TXT_KEY_DQ_LEADER_NAME_5">
<Text>Winston Churchill</Text>
</Row>
<Row Tag="TXT_KEY_DQ_LEADER_NAME_5_QUOTE">
<Text>A pessimist sees the difficulty in every opportunity; an
optimist sees the opportunity in every difficulty.</Text>
</Row>
<Row Tag="TXT_KEY_DQ_LEADER_NAME_6">
<Text>Nelson Mandela</Text>
</Row>
<Row Tag="TXT_KEY_DQ_LEADER_NAME_6_QUOTE">
<Text>It always seems impossible until its done.</Text>
</Row>
<Row Tag="TXT_KEY_DQ_LEADER_NAME_7">
<Text>Marcus Aurelius</Text>
</Row>
<Row Tag="TXT_KEY_DQ_LEADER_NAME_7_QUOTE">
<Text>Because a thing seems difficult for you, do not think it
impossible for anyone to accomplish.</Text>
</Row>
<Row Tag="TXT_KEY_DQ_LEADER_NAME_8">
<Text>Joan of Arc</Text>
</Row>
<Row Tag="TXT_KEY_DQ_LEADER_NAME_8_QUOTE">
<Text>I am not afraid... I was born to do this.</Text>
</Row>
<Row Tag="TXT_KEY_DQ_LEADER_NAME_9">
<Text>Charles de Gaulle</Text>
</Row>
<Row Tag="TXT_KEY_DQ_LEADER_NAME_9_QUOTE">
<Text>Faced with crisis, the man of character falls back on
himself. He imposes his own stamp of action, takes responsibility
for it, makes it his own.</Text>
</Row>
<Row Tag="TXT_KEY_DQ_LEADER_NAME_10">
<Text>Simon Bolivar</Text>
</Row>
<Row Tag="TXT_KEY_DQ_LEADER_NAME_10_QUOTE">
<Text>Judgement comes from experience, and experience comes from
bad judgement.</Text>
</Row>
<Row Tag="TXT_KEY_DQ_LEADER_NAME_11">
<Text>Lech Walesa</Text>
</Row>
<Row Tag="TXT_KEY_DQ_LEADER_NAME_11_QUOTE">
<Text>He who puts out his hand to stop the wheel of history will
have his fingers crushed.</Text>
</Row>
<Row Tag="TXT_KEY_DQ_LEADER_NAME_12">
<Text>Ivan the Terrible</Text>
</Row>
<Row Tag="TXT_KEY_DQ_LEADER_NAME_12_QUOTE">
<Text>Withal, I concern myself greatly regarding the affairs of
state, constant wars against hostile nations, and the welfare of
my poor people.</Text>
</Row>
<Row Tag="TXT_KEY_DQ_LEADER_NAME_13">
<Text>Henry VIII</Text>
</Row>
<Row Tag="TXT_KEY_DQ_LEADER_NAME_13_QUOTE">
<Text>My Lord, if it were not to satisfy the world, and my Realm,
I would not do that I must do this day for none earthly
thing.</Text>
</Row>
<Row Tag="TXT_KEY_DQ_LEADER_NAME_14">
<Text>Herbert Hoover</Text>
</Row>
<Row Tag="TXT_KEY_DQ_LEADER_NAME_14_QUOTE">
<Text>Blessed are the young for they shall inherit the national
debt.</Text>
</Row>
<Row Tag="TXT_KEY_DQ_LEADER_NAME_15">
<Text>Louis XVI</Text>
</Row>
<Row Tag="TXT_KEY_DQ_LEADER_NAME_15_QUOTE">
<Text>Listeners never hear any good of themselves.</Text>
</Row>
<Row Tag="TXT_KEY_DQ_LEADER_NAME_16">
<Text>Neville Chamberlain</Text>
</Row>
<Row Tag="TXT_KEY_DQ_LEADER_NAME_16_QUOTE">
<Text>In war, whichever side may call itself the victor, there
are no winners, but all are losers.</Text>
</Row>
<Row Tag="TXT_KEY_DQ_LEADER_NAME_17">
<Text>Andrew Jackson</Text>
</Row>
<Row Tag="TXT_KEY_DQ_LEADER_NAME_17_QUOTE">
<Text>There is no pleasure in having nothing to do; the fun is
having lots to do and not doing it.</Text>
</Row>
<Row Tag="TXT_KEY_DQ_LEADER_NAME_18">
<Text>Nero</Text>
</Row>
<Row Tag="TXT_KEY_DQ_LEADER_NAME_18_QUOTE">
<Text>So great an artist, I die!</Text>
</Row>
<Row Tag="TXT_KEY_DQ_LEADER_NAME_19">
<Text>Warren G. Harding</Text>
</Row>
<Row Tag="TXT_KEY_DQ_LEADER_NAME_19_QUOTE">
<Text>Somewhere there must be a book that tells all about it,
where I could go to straighten it out in my mind. But I don't
know where the book is, and maybe I couldn't read it if I found
it.</Text>
</Row>
<Row Tag="TXT_KEY_DQ_LEADER_NAME_20">
<Text>Ethelred the Unready</Text>
</Row>
<Row Tag="TXT_KEY_DQ_LEADER_NAME_20_QUOTE">
<Text>Yeah, just five minutes, all right?</Text>
</Row>
<Row Tag="TXT_KEY_DQ_LEADER_NAME_21">
<Text>Dan Quayle</Text>
</Row>
<Row Tag="TXT_KEY_DQ_LEADER_NAME_21_QUOTE">
<Text>If we don't succeed, we run the risk of failure.</Text>
</Row>