On Wednesday, Missouri Treasurer Clint Zweifel contacted a woman from Kansas City and told her she will receive the monetary value of a property she didn't even know she owned. The single security property, likely either a bond or a stock, was worth $6.1 million, making it the largest unclaimed property in the state of Missouri, and possibly in U.S. history, too.

The woman has requested to remain anonymous for her own safety.

It's a huge amount of money, Zweifel reportedly said. Ultimately we have a responsibility, when we return money back to somebody, to protect their privacy and to make sure they're not being tracked or followed by someone. And it recognizes that this ist heir money.

Sources from Kansas City say the woman's single security was actually an investment in an obscure company, made by the woman's relative several years ago. The sources did not say which company this was, or how much the company is worth now, but when the woman found out, she reportedly asked the Treasurer's Office to sell the security for a cash payment.

The woman will still have to pay taxes on her unexpected pile of cash, but she may not mind considering she wasn't expecting any such money.

Other people have received large unclaimed money payouts, but none so big as this particular case. New York once held the record for the largest unclaimed money payout when it returned about $4 million. Wisconsin also once returned about $1.5 million, while Zweifel says a Missouri man once received $100,000 from unclaimed money in more than 15 different securities accounts. The state has returned $103 million in unclaimed money to more than 300,000 people since January 2009.

There is so much money that's out there waiting for Americans to claim, Zweifel said. Just to give you an example, in Missouri alone I have more than $600 million on hand waiting for Missourians.

Every U.S. states, Missouri included, has established protocols for distributing property that hasn't been claimed for at least five years. Many states issue stocks, bonds, safety deposit boxes, government refunds and bank accounts. State agencies say most claims can be made into perpetuity, so even heirs can claim the property if the original owner cannot be found.

The National Association of Unclaimed Property Administrators (NAUPA) says one in every 10 people has unclaimed money waiting for them, and billions of dollars are lost every year in unclaimed funds; New York state alone has $11 billion in unclaimed cash, and has a system for owners to claim their funds they may not know were lost. NAUPA also endorses a website called MissingMoney, which contains the official collective records from most state's unclaimed property programs.

Property is typically lost when a company loses contact with an individual, whether it's because of an address change or change in marital status. Many financial institutions don't forward mail for security purposes, so NAUPA's directories and MissingMoney's platform are good options to find accurate financial records and claims.