Signatures of classic US political figures were the boom sector in the 2015 autographs market. Why so? Could it be collectors harking back to a golden era of US politics, in reaction to the circus the campaign trail has become?
In general, there was slow and steady growth in values for many signers, with the PFC40 Autograph Index tracking an increase of 2.4% on the most popular autographs between 2014 and 2015.
Some more unusual names popped up at the top of the market too. Find out more below…
Top autograph sale of 2015
The top autograph sale of 2015 was a handwritten page from Abraham Lincoln's second inaugural speech, penned by the man himself.
It realised $2.2m at Heritage Auctions in November.
There are only five known handwritten copies of the speech extant, making it a big draw for collectors.
Lincoln letters and signatures are not particularly rare - it was the important historical content of the text that led to such a strong sale.
2015's most important autograph sales
This year saw a new world record set for Charles Darwin, after a Darwin-signed letter stating his atheism sold for $197,000. It led a sale at Bonhams in September.
Meanwhile, a letter by William Henry Harrison sold for $75,000 at Christie's in June. Harrison was the shortest-lived US president in history, with only 32 days in office. Memorabilia dating to his brief administration is thus extremely rare.
Memorabilia relating to Mexican artist Frida Kahlo seldom comes to auction, so it was a treat to see a collection of love letters make $137,000 at Doyle New York in April.
A signed copy of Dr Martin Luther King's Stride Toward Freedom was another highlight, achieving $49,500 at Hake's. It's inscribed to Chief Justice Earl Warren, who helped overturn segregation in American schools.
The most unusual autograph sale of 2015
A touching letter from Enigma codebreaker Alan Turing to the daughter of his psychologist sold for �40,000 ($62,943) in June.
In the note Turing explains the rules of Solitaire. Sadly he would take his own life just a few months later.
It was a breakout year for…
Mao Zedong wrote to British Labour party leader Clement Attlee in 1937 (after the Japanese invasion), requesting help.
That letter crossed the block in a December auction at Christie's London, making �605,000 ($917,319). It is only the second Mao signature to auction in recent years.
It was a year to forget for…
A rare Button Gwinnett signature failed to sell in an auction at Mullock's in Shropshire, UK in October.
Gwinnett was one of the lesser known signatories of the Declaration of Independence, and consequently one of the rarest. This makes his autograph a key piece for collectors looking for the full set.
The fact that the signature was offered in the UK likely affected its chances of success.
One you may have missed…
An intriguing find was made in Japan in January, when American author and activist Hellen Keller's signature turned up in a textbook from 1937.
Keller loved Japan and visited on three occasions throughout her life.