Bessel used parallax to determine the distance to 61 Cygni announcing his result in 1838. Clearly to succeed it was important to choose a star which was close to the Sun. His method of selecting a star was based on his own data for he chose the star which had the greatest proper motion of all the stars he had studied, correctly deducing that this would mean that the star was nearby. Since 61 Cygni is a relatively dim star it was a bold choice based on his correct understanding of the cause of the proper motions. Bessel, using a Fraunhofer heliometer to make the measurements, announced his value of 0.314" which given the diameter of the Earth's orbit, gave a distance of about 10 light years. The correct value of the parallax of 61 Cygni is 0.292".John Herschel, when he learnt of Bessel's achievement, wrote to him describing it as: "... the greatest and most glorious triumph which practical astronomy has ever witnessed."
Olbers, told of Bessel's achievement on his 80th birthday, said it was a gift that: "... put our ideas about the universe for the first time on a sound basis."
The Royal Astronomical Society awarded him their gold medal to mark this achievement.
The first attempts to determine parallaxes using photography were done during the period 1887-1889 by Pritchard at Oxford. Although there was considerable debate over the merits and even possibility of doing astrometry using photographs, photography turned out to be an excellent way to measure parallaxes, as the accuracy was much greater than using visual methods and the labor was much less intensive. Furthermore, by taking a photograph, a permanent record was made of the measurement, so that the image could be examined at once or later, and it could be remeasured again and again for new information. In 1900 Kapteyn designed a systematic method to take these photographs, in allowing each photographic plate to be exposed three times during a single night, and four nights spaced throughout the year, such that in the end there are twelve exposures for every star on the plate.
Of course. (smacks forehead). The trusty ol' "Fraunhofer heliometer"!