  First-generation long-distance quantum repeater networks require quantum
memories capable of interfacing with telecom photons to perform
quantum-interference-mediated entanglement generation operations. The ability
to demonstrate these interconnections using real-life fiber connections in a
long-distance setting is paramount to realize a scalable quantum internet. Here
we address these significant challenges by observing Hong-Ou-Mandel (HOM)
interference between indistinguishable telecom photons produced in two
independent room temperature quantum memories, separated by a distance of 158
km. We obtained interference visibilities after long-distance propagation of
$\rm \boldsymbol{V=(38\pm2)\%}$ for single-photon level experimental inputs.
This first-of-its-kind quantum network prototype connecting quantum
laboratories in Stony Brook University and Brookhaven National Laboratory is
envisioned to evolve into a large-scale memory-assisted entanglement
distribution quantum network, the basis for inter-city quantum communication.
