Bills of Exchange: A Proto-Blockchain?
In the early 1800s, bills of exchange were a means of conducting a transaction that depended on a lack of anonymity. When converted into a multiple-signature paper, I think that they looked like a proto-blockchain.
A bill of exchange is a written order that commits one party to pay a sum of money to another on demand or at a set date. They can be drawn by individuals or banks and transferred by endorsement.
This last attribute made them cash-like. You could pass on a bill of exchange as a means of payment by endorsing it. By endorsing, you became liable for payment. As it changed hands, it would accumulate a list of signatures on the back.
When you wanted to redeem it, you would go up the list of signatories. If the last signer said he couldn't pay, you'd go up to the next person, and so on until someone paid. (You had a chain of transactions in which each previous one was approved before a new transaction occurred. Sound familiar?)
If you were accepting a bill of exchange, you really wanted to know the credit of the original issuer. If you didn't know that, you would look at the list of endorsers. The more endorsers, the better. More signers denoted not only confidence in the issuer or previous signer, the list of endorsers also gave you more chances to get your money. (Some kind of non-crypto proof of stake on the signers' parts as they are staking their reputations?)