user74511: I'm looking at nonce data from blockchain.info for block #1 ( https://blockchain.info/block/00000000839a8e6886ab5951d76f411475428afc90947ee320161bbf18eb6048 ) and it shows a nonce value of 2573394689 However when I take a look at blockcypher.com ( https://api.blockcypher.com/v1/btc/main/blocks/1 ) they report a nonce value of 2083236893 for the first block. 
Is this a mistake? Is it possible for there to be a conflict in the true nonce? When I check block #2 both sites show the exact same nonce.

user71774: The block presented with the second link (api.blockcypher.com/v1/btc/main/blocks/1) is not the same as the one presented with blockchain.info.
"api.blockcypher.com" says block 1 (Height=1) has a "previous block" of all zeroes:

but that is the block with Height=0, not with Height=1 !.
One could argue that "api.blockcypher.com" starts counting (oddly) on "1", but the problem is that their next block (block 2) has a "previous block" of "00000000839a8..." (correct) which in fact is not their block 1...
That is, there is a gap in their API, and the block with a "previous block"="000000000019d66..." or block with Height=1, is not accessible using block count:

"api.blockcypher.com" block 1 is really the block 0 (Height=0), and 
their block 2 is the correct block 2 (Height=2), and so 
the block 1 that you are trying to see is unreachable in that API (!).

That also means that Nonce=2573394689 for block 1 from blockchain.info is the correct value.

74511: <p>I'm looking at nonce data from blockchain.info for block #1 ( <a href="https://blockchain.info/block/00000000839a8e6886ab5951d76f411475428afc90947ee320161bbf18eb6048" rel="nofollow noreferrer">https://blockchain.info/block/00000000839a8e6886ab5951d76f411475428afc90947ee320161bbf18eb6048</a> ) and it shows a nonce value of <strong>2573394689</strong> However when I take a look at blockcypher.com ( <a href="https://api.blockcypher.com/v1/btc/main/blocks/1" rel="nofollow noreferrer">https://api.blockcypher.com/v1/btc/main/blocks/1</a> ) they report a nonce value of <strong>2083236893</strong> for the first block. </p>

<p>Is this a mistake? Is it possible for there to be a conflict in the true nonce? When I check block #2 both sites show the exact same nonce.</p>
 71774: <p>The block presented with the second link (<a href="https://api.blockcypher.com/v1/btc/main/blocks/1" rel="nofollow noreferrer">api.blockcypher.com/v1/btc/main/blocks/1</a>) is not the same as the one presented with <a href="https://blockchain.info/block/00000000839a8e6886ab5951d76f411475428afc90947ee320161bbf18eb6048" rel="nofollow noreferrer">blockchain.info</a>.</p>

<p>"<strong>api.blockcypher.com</strong>" says block 1 (Height=1) has a "previous block" of all zeroes:
<a href="https://i.stack.imgur.com/tOvKO.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/tOvKO.png" alt="enter image description here"></a>
but <a href="https://bitcoin.org/en/glossary/block-height" rel="nofollow noreferrer">that is the block with Height=0</a>, not with Height=1 !.</p>

<p>One could argue that "api.blockcypher.com" starts counting (oddly) on "1", but the problem is that <a href="https://api.blockcypher.com/v1/btc/main/blocks/2" rel="nofollow noreferrer">their next block</a> (block 2) has a "previous block" of "00000000839a8..." (correct) which in fact is not their block 1...</p>

<p>That is, <strong>there is a gap in their API</strong>, and the block with a "previous block"="000000000019d66..." or <strong>block with Height=1, is not accessible</strong> using block count:</p>

<ul>
<li>"api.blockcypher.com" block 1 is really the block 0 (Height=0), and </li>
<li>their block 2 is the correct block 2 (Height=2), and so </li>
<li><strong>the block 1 that you are trying to see is unreachable in that API</strong> (!).</li>
</ul>

<p>That also means that <strong>Nonce=2573394689</strong> for <a href="https://blockchain.info/block/00000000839a8e6886ab5951d76f411475428afc90947ee320161bbf18eb6048" rel="nofollow noreferrer">block 1 from blockchain.info</a> is the correct value.</p>
