Use the free search tool at: https://familysearch.org/search to search for records. Here are some on Juan F. Flinn. There are a few more there. If you are interested in his ancestry - plug in the names/dates/locations of his parents/siblings etc to try to find more.
Maine, State Archive Collections, 1718-1957
Citing this Record: "Maine, State Archive Collections, 1718-1957", index and images, FamilySearch (https://familysearch.org/pal:/MM9.1.1/246N-K7W : accessed 26 Jul 2014), Juan F Flinn, 1864.
IMAGE SOURCE: https://familysearch.org/pal:/MM9.3.1/TH-1942-21941-45405-56?cc=1877829
Name: Juan F Flinn
Military Service 13 Feb 1864 Place: Newburg,
Age: 26 Single
Birth (Est): 1838 Birthplace: Newburg,
Affiliate Publication Title: Maine, Civil War Soldiers and Sailors Card Index, 1861-1865
Maine, Deaths and Burials, 1841-1910
Citing this Record: "Maine, Deaths and Burials, 1841-1910," index, FamilySearch (https://familysearch.org/pal:/MM9.1.1/F4ZV-92F ), Juan F., Private Flinn, 02 Jun 1865; citing reference 84; FHL microfilm 11583.
Name: Juan F., Private Flinn Male
Death Date: 02 Jun 1865
Age: 27 Birth Date: 1838
United States Census, 1860 Newburgh, Penobscot, Maine
Citing this Record: "United States Census, 1860," index, FamilySearch (https://familysearch.org/pal:/MM9.1.1/MDCQ-M4R), Juan F Flynn in household of Thomas Flynn, Newburgh, Penobscot, Maine, United States; citing "1860 U.S. Federal Census - Population," Fold3.com; p. 43, household ID 332, NARA microfilm publication M653; FHL microfilm 803445.
Thomas Flynn M 70 Mass
Ruth A Flynn F 64 Maine
Juan F Flynn M 23 Maine
William Flemont M 10 Maine
Almeda Flemont F 8 Maine
Ruth E Flynn F 20 Maine