Pictured above is the former $100,000 bill, which was backed in gold and printed in 1934 (Therefore were not valid for common citizens, as the ownership of gold as money was banned by Franklin Roosevelt a year earlier). Other notes that were printed included $500, $1,000, $5,000, and $10,000. They were primarily used by banks and government institutions but were stopped by President Nixon by executive order. Apparently one of the reasons for this decision was to “make life harder for the Mafia”, who were infamous for peddling in cash.
The biggest point that comes to mind now, is whether or not as our currency takes a blow from inflation in the coming years, will larger denominations be required? In China, the 100 RMB note is the highest denomination and is worth $14.6462. In Europe the largest single bill is 500 Euros, which is equivalent to $742.4. In a side note, every reputable currency except the USD has its notes of different sizes as to aid those who are visually impaired.
Personally, my favorite form of the USD is in coin form or two dollar bills.